Patent Publication Number: US-7721783-B2

Title: Horizontally slatted blind

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a nonprovisional application having a claim for priority based on U.S. Patent Application Ser. No. 60/818,118, filed Jun. 30, 2006. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to horizontally slatted blinds, that is, to Venetian blinds, and more particularly to blinds of this general type having slats which are cantilevered. 
     2. Description of the Relevant Art 
     Venetian blinds, of course, are well-known in the art. Indeed, they are ubiquitous and can be found in homes and offices around the world. 
     Cantilevered blinds of this general type have slats which turn, to open or close the blind, about axes which do not coincide with the centers of the slats. The axes, instead, are typically closer to the opening, such as a window, than the geometric centers of the slats so that, when the blind is closed, the slats will be close to the window or opening. 
     The relevant art includes several examples of this general type of blind. U.S. Pat. No. 1,590,886 to Carella, for example, shows a window blind having spaced vertically disposed chains having their opposite ends secured to the top and bottom of the window frame. Slats are mounted one above the other on the chains, pivoting about the chain links to which they are attached. A cable, attached to each of the slats, is used to open or close the blind. This blind, however, has no means for being raised or lowered as a whole. Whether opened or closed, the blind always extends for the full height of the window because the chains are secured to the top and bottom of the frame. 
     U.S. Pat. No. 2,583,449 to Tarnoff shows an elaborate Venetian blind having slats cantilevered in front of a mechanical linkage which collapses as the blind is raised from its bottom. The slats may be opened or closed by turning the rod from which the mechanical linkage is suspended. The slats themselves are entirely free of tapes and cords, and may be easily cleaned. 
     U.S. Pat. No. 5,165,459 to Gaber et al. shows a window covering having a head rail and a plurality of slats suspended therefrom. The slats are adapted to pivot and thereby contact contiguous slats to form dead air cells for improved appearance and insulating properties. The cords which raise and lower the window covering and which open and close the slats pass through holes therein. The slats may be pivoted in a cantilevered manner, that is, they may be pivoted about an axis not coincident with their centers, by providing opposite sides of the slats with different weight. 
     Finally, U.S. Pat. Nos. 6,405,783 and 6,557,615 to Smith, which patents are related to one another, show a horizontal window blind apparatus having slats which are cantilevered outward from tabs. The tabs are raised, lowered and tilted in a manner similar to that employed in a conventional Venetian blind. 
     Notwithstanding these cantilevered blinds of the relevant art, there remains a need for a horizontally slatted blind having slats which are wider than those customarily used in Venetian blinds. There further remains a need for such a blind whose slats have no holes through which light would be able to leak from outside into a room. Moreover, there remains a need for a blind which will hang closely adjacent to a window when closed, so that light will be less able to pass around its ends into a room. These needs are met by the present invention. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is a horizontally slatted blind which is designed to hang in close proximity to a window when closed. The blind comprises a header for mounting the blind across an opening. Mounted within the header is a rod which extends longitudinally therein. The rod has a first and second end and a longitudinal axis, and is rotatable about its longitudinal axis. 
     A plurality of slats is disposed horizontally and spaced vertically below the header. Each slat in the plurality of slats has a first end and a second end, a front corner at each of the first and second ends and a rear corner at each of the first and second ends. Each slat also has a stiffener which extends substantially from the rear corner at its first end to the rear corner at its second end. 
     First tilt cords and second tilt cords are attached to and extend from each of the first and second ends of the rod. The first tilt cords are attached to the first and second ends of the slats at points between their front and rear corners and the second tilt cords are attached to the first and second ends of the slats substantially at the rear corners. This places the axis of rotation of each slat at a point between the attachment points for the first and second tilt cords, namely, more toward the rear, or window, from where the axis of rotation would be if geometrically centered. As a consequence, the closed blind will be closer to the window than a conventional blind. 
     The stiffeners are provided for two reasons. Firstly, since the axes of rotation are closer to the rear of the slats than to the front, the stiffeners act as counterweights to the wider portions of the slats on the other side of the axes of rotation, thereby enabling each slat to be balanced about its axis of rotation. Secondly, since each slat may only be suspended from points on its first and second ends, the stiffeners are provided to prevent them from sagging below the first and second ends. 
     Finally, the blind comprises means for attaching the first and second tilt cords to the first and second ends of the rod whereby, when the rod is rotated about its longitudinal axis, one of the first and second tilt cords is lowered while the other of the first and second tilt cords is raised by an equal amount, so that the plurality of slats open or close in unison. 
     The present invention will now be described in more complete detail with frequent reference being made to the accompanying drawings, which are identified below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an end view of several slats in an open hypothetical horizontally slatted blind; 
         FIG. 1B  is an end view of the blind shown in  FIG. 1A  when closed; 
         FIG. 2A  is an end view of several slats in another open hypothetical horizontally slatted blind; 
         FIG. 2B  is an end view of the blind shown in  FIG. 2A  when closed; 
         FIG. 3  is a perspective view of the horizontally slatted blind of the present invention; 
         FIG. 3A  is a schematic view of the interior of the header of the blind shown in  FIG. 3 ; 
         FIG. 4  is a perspective view of the end of one slat of the blind shown in  FIG. 3 ; 
         FIG. 5  is an exploded view of the end of the slat shown in  FIG. 4 ; 
         FIG. 5A  is a perspective view of an end portion of a flat (planar) slat; 
         FIG. 5B  is a perspective view of an end portion of a sinusoidally undulating slat; 
         FIG. 6  is a perspective view, partly exploded, of the ends of two slats in an alternate attachment arrangement; 
         FIG. 7  is a perspective view, also partly exploded, of the end of one slat shown in  FIG. 6 ; 
         FIG. 8  is a perspective view, analogous to that shown in  FIG. 3 , illustrating the suspension of the slats in the present horizontally slatted blind; 
         FIG. 9  is a perspective view, analogous to that given in  FIG. 8 , of an alternate approach for suspending the slats; 
         FIGS. 10 and 11  illustrate one means for attaching a center cord to a slat; 
         FIG. 12  shows an alternate means for attaching a center cord to a slat; 
         FIG. 13  is an exploded plan view of the end of a slat; and 
         FIG. 14  is another plan view of the end of a slat. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before describing the present invention in more particular detail, it will be useful to illustrate its basic rationale. The present invention provides a blind with slats which are generally wider than the norm, perhaps as wide as 3.5 inches or more. The present invention additionally provides a blind whose slats lack the holes normally required for ladder and lift cords, as these cords are disposed at the ends of the slats. In other words, when the blind is closed, light cannot leak through the slats into the room. 
     Referring now to  FIG. 1A , which is an end view of several slats  12  in a hypothetical horizontally slatted blind  10  in front of a window  14 , tilt cords  16 ,  18  are attached to the corners of the ends of the slats  12 . When the blind  10  is open, as shown in  FIG. 1A , the slats  12  are relatively close to the window  14 . 
     When blind  10  is to be closed, the customarily used mechanism simultaneously lowers tilt cord  16  and raises tilt cord  18 , or vice versa, turning each slat  12  about an axis of rotation which generally coincides with the center of the width of each.  FIG. 1B , an end view of the slats  12  when the blind  10  has been closed, the tilt cord  16  having been moved in a downward direction and the tilt cord  18  having been moved in an upward direction, as indicated by the arrows, shows that the slats  12  are considerably farther from the window  14  when the blind  10  is closed than it is when open. In such a situation, light from outside the window  14  is better able to pass into the room from around the ends of the slats  12  than it would if it were possible for the closed blind  10  to be closer to the window  14 . 
     The present invention provides a solution to this problem by moving the axes of rotation of the slats closer to the window  14  so that, when the blind  10  is closed, the slats  12  remain substantially as close to the window  14  as they are when the blind  10  is open. 
     Referring to  FIG. 2A , hypothetical horizontally slatted blind  20  having several slats  22  is shown in an end view in front of a window  24 . Blind  20  is open in  FIG. 2A , where tilt cords  26 ,  28  are attached to the ends of the slats  22 . Tilt cord  26  is attached to the end of the slats  22  at a point somewhere between the two corners of the slats  22 , while tilt cord  28  is attached to the corner of the slats  22  closest to the window  24 . When the blind  20  is open, the slats  22  are relatively close to the window  24 . 
     When blind  20  is to be closed, the customarily used mechanism simultaneously lowers tilt cord  26  and raises tilt cord  28 , or vice versa, turning each slat  22  about an axis of rotation which is at a point between the tilt cords  26 ,  28 .  FIG. 2B , an end view of the slats  22  when the blind  20  has been closed, the tilt cords  26 ,  28  having been moved in the directions indicated by the arrows, shows that the slats  22  when blind  20  is closed are approximately the same distance from the window  24  as they are when blind  20  is open. In such a situation, light from outside the window is less able to pass into the room from around the ends of the slats  22 . 
     It will be readily apparent to one of ordinary skill in the art, however, that the slats  22  in blind  20  would not be balanced, and would tend to close quickly to the position shown in  FIG. 2B  if released because a greater portion of the width of each slat  22  is located to the left (in the figure) of the axis of rotation, located between the tilt cords  26 ,  28 , than to the right. As will be discussed in greater detail below, additional weight is added to the right-side (in the figure) edge of each slat, that edge being closer to the window, to act as a counterweight to bring the slats  22  into balance about their geometrically off-centered axes of rotation, allowing them to be set to any desired angle and to remain at any desired angle. 
     Turning now more specifically to the present invention,  FIG. 3  is a perspective view of the horizontally slatted blind  30  of the present invention. The blind  30  includes a header  32  by which the blind  30  may be mounted onto the top of a window frame. The blind  30  includes a plurality of horizontally extending slats  34 , three of which are shown in the figure. A stiffener  36  is attached to the rear edge of each slat  34 , the stiffener  36  providing the additional weight, that is, the counterweight, required to balance the slats  34  about axes of rotation located between the tilt cords  38 ,  40 . The stiffener  36  also provides the slat  34  with additional rigidity as may be needed when the window is wide. 
     As the slats  34  are considerably wider than the header  32  in the present invention, a traditional wand, hanging in front of the slats  34 , is not used to adjust the angle thereof to open and close the blind  30 . Rather, a handle  42 , snapped onto one of the slats  34 , is used to make this adjustment manually. A lift cord  44  is provided to enable the blind  30  to be raised and lowered from the bottom. As shown in  FIG. 3A , the lift cord  44  passes into the header  32  and over pulleys  45  therein to run as two portions  44 ′, 44 ″ down the two opposite ends of the slats  34 , in a manner to be shown below in greater detail. The blind  30  of the present invention is intended to run for as close to the entire width of the window in which it is to be used as possible in order to minimize the amount of the light that may be able to leak around its edges into a room. 
       FIG. 4  is a perspective view of the end of one slat  34  of the blind  30  shown in  FIG. 3 . At the end of the slat  34 , a first end piece  46  is disposed adjacent to the end of the slat  34  and a second end piece  48  is disposed outwardly from the first end piece  46 . A spacer  50  maintains gaps  52  between the first and second end pieces  46 ,  48 . Tilt cords  38 ,  40  are mounted within gaps  52  in a manner to be shown more clearly in the exploded view to follow. Lift cord  44  also passes through the rearmost gap to enable the slats  34  to be stacked upon one another from below when the blind  30  is raised. 
       FIG. 5  is an exploded view of the end of slat  34  shown in  FIG. 4 . Slat  34  may be of plastic, aluminum, plastic with a wooden veneer, stiffened fabric or of any other material used by those of ordinary skill in the art to make slats for Venetian blinds. The slats  34  may be curved, as shown in  FIGS. 4 and 5 , but they need not be as shown in those figures. For example, they may be flat (planar), like slat  34 ′ in  FIG. 5A , or sinusoidally curved, like slat  34 ″ in  FIG. 5B , giving them a wavy appearance. 
     Stiffener  36  may be extruded from plastic or aluminum, or from other suitable materials. Stiffener  36  includes a groove  54  into which slat  34  is inserted. An adhesive may be used to secure the slat  34  within the groove  54 . Alternatively, the slat  34  may be held in the groove  54  mechanically with an interference fit. 
     The stiffener  36  has a central hole  56  running longitudinally therethrough. Additional weight may be inserted therein if required to balance the slat  34 , depending on the material from which slat  34  is made. 
     First end piece  46  has an insert  58  which fits into hole  56  in stiffener  36 . Insert  58  may be held in hole  56  with an adhesive or by force fitting. First end piece  46  may have a groove (not shown) into which the end of the slat  34  may fit when first end piece  46  is attached to the stiffener  36 , so that slat  34  may be stabilized relative thereto. First end piece  46  may also have a hole  60  for use in connecting second end piece  48  thereto, and is preferably molded from a plastic material. 
     Tilt cords  38 ,  40  may be made from plastic monofilament or from braided stainless steel cable. Cylindrical pins  62  are bonded or swedged thereto at appropriate intervals, the tilt cords  38 ,  40  passing through holes  64  directed transversely therethrough. First end piece  46  has holes  66  into which one end of each cylindrical pin  62  fits. 
     Second end piece  48  also has holes  68  for the other end of each cylindrical pin  62 , and has a snap-lock connector  70  which engages within hole  60  in first end piece  46  to complete the construction. Second end piece  48  is also preferably molded from a plastic material. 
     Alternative means for mounting the slats  34  are shown in  FIGS. 6 and 7 , both of which are exploded perspective views. Referring first to  FIG. 6 , standard ladder cord  72 , comprising tilt cords  74 ,  76  which are joined at regular intervals by cross cords  78 , is used to open and close the blind. Cross cords  78  are enclosed between first end pieces  80  and second end pieces  82 , the latter of which being cover caps. As above, first end pieces  80  include inserts  84  which fit into holes  56  in stiffeners  36 , and may include a groove (not shown) into which the end of the slat  34  may fit when first end piece  80  is attached to stiffener  36 . The lift cord  44  again passes between the first and second end pieces  80 ,  82 . 
     Referring to  FIG. 7 , first end piece  80  is shown attached to stiffener  36 , but separated from second end piece  82 , which includes a snap-lock connector  86  for connecting it to first end piece  80  by engaging in hole  88  in first end piece  80 . First and second end pieces  80 ,  82  may alternatively or additionally be secured to one another by ultrasonic or adhesive bonding. 
     First end piece  80  also includes several lugs  90 , namely, a pair of adjacent lugs  90  at each end of the first end piece  80 , so that cross cords  78  may be directed between each pair  80  as to be held in position when the second end piece  82  is secured thereover. In this respect, the lugs  90  act as spacers between the first and second end pieces  80 ,  82  to provide sufficient clearance for lift cord  44  to pass between them. Both the first and second end pieces  80 ,  82  are preferably molded from a plastic material. 
       FIG. 8  is a perspective view, analogous to that shown in  FIG. 3 , illustrating the manner in which the slats  34  may be suspended from the header  32 . Within the header  32  is a rod  92  which runs for the length of the header  32  and substantially for the full width of the blind  30 . At each end of the rod  92  is a cross member  94 . Tilt cords  38 ,  40  are attached to opposite ends of the cross member  94 . When the blind  30  is to be opened or closed by means of handle  42 , tilt cords  38 ,  40  act on cross member  94  to rotate it about the longitudinal axis of the rod  92 , thereby rotating rod  92  and the cross member and the cross member  94  on the far end of the rod  92  to raise or lower the tilt cords  38 ,  40  at that end, so that the slats  34  may be opened or closed evenly on both ends of the blind  30 . 
     At one or more points between the two ends of the rod  92 , an auxiliary cross member  96  may be mounted to turn therewith. Auxiliary cross member  96 , oriented generally toward the rear of the slats  34  to which stiffeners  36  are attached, is provided where the blind  30  is wide to suspend one or more center cords  98  down the rear side of the blind  30  and attached to each slat  34  in a manner to be described below to prevent long slats  34  from sagging. 
     An alternate means for suspending the slats  34  from the header  32  is shown in  FIG. 9 , a perspective view analogous to that provided in  FIG. 8 . Again, a rod  100  runs for the length of the header  32  and substantially for the full width of the blind  30 . Tilt cords  38 ,  40  are wound around each end of the rod  100  in opposite directions in the manner of a capstan and attached thereto with a set screw  103 . When the blind  30  is to be opened or closed, tilt cords  38 ,  40  at one end of the rod  100  rotate it about its longitudinal axis, which rotation, raises or lowers the tilt cords  38 ,  40  at the far end of the rod  100  in a corresponding manner, so that the slats  34  may be opened or closed evenly on both ends of the blind  30 . 
     Again, at one or more points between the two ends of the rod  100 , center cord  102  may be wound therearound in the same direction as tilt cord  40  and attached thereto by a set screw  105  for attachment to each slat  34  in a manner to be described below to prevent long slats  34  from sagging. 
       FIGS. 10 and 11  illustrate one approach for connecting a center cord to each slat. Center cord  104  passes at regular intervals through holes  106  transversely directed through cylindrical pins  108 , and is bonded or swedged thereto as described above. A notch  110  is provided in the stiffener  36 , as well as an opening  112  on its underside to enable the pin  108  to be lodged therein before the slat  34  is inserted into the stiffener  36 . Once the slat  34  is so inserted, the pin  108  cannot be removed. Center cord  104  is thereby held within the notches  110  in the stiffeners  36  as illustrated. 
     Alternatively, as shown in  FIG. 12 , center cord  112  could be obtained by cutting through the cross cords of a standard ladder cord. Clips  114  attached to the severed cross cords  116  may be snapped onto the stiffeners  36  on the slats  34  to provide the required center support for a long slat  34 . 
     As noted above, grooves may be provided in first end pieces  46 ,  80  to stabilize slats  34  relative thereto when first end pieces  46 ,  80  are attached to stiffeners  36 . Referring to  FIG. 13 , an alternate approach for stabilizing the slat  34  is to provide the slat  34  with a tab  118  and first end piece  46 , or first end piece  80 , with a slot  120  to accommodate tab  118  when first end piece  46  is attached to stiffener  36 . 
       FIG. 14  is a plan view of the end of a slat  34  showing a further optional modification to its shape. Slat  34  is shown as it would appear from above in an open blind  30 . First and second end pieces  46 ,  48  are attached to slat  34  by way of stiffener  36 . Slat  34  widens at point  122  at the end of the first and second end pieces  46 ,  48  by an amount equal to their combined thickness as shown in  FIG. 14 . As a consequence, when the blind  30  is closed, the slat  34  above that shown will cover the first and second end pieces  46 ,  48  and hide the tilt cords  38 ,  40  from view. 
     Modifications to the above 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.