Abstract:
A looped-cord tensioner for an architectural covering including a housing adapted for attachment to a looped-cord, an abutment member positioned within the housing, a slide member positioned within the housing, and at least one biasing element having a first end and a second end. One of the slide member and the abutment member is adapted to engage the second end of the biasing element and the first end of said biasing element is adapted to engage the housing such that one of the slide member and the abutment member is moveably positioned in the housing so as to bias one of the slide member and the abutment member toward engagement with the looped-cord such that the looped-cord is normally non-movably sandwiched between the slide member and the abutment member prior to installation of the looped-cord tensioner. One of the slide member and the housing is adapted to be fixedly installed to a non-movable structure adjacent the architectural covering such that one of the slide member and the abutment member is disengaged from the looped-cord and the looped-cord is free to moveably pass through the housing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to looped-cord tensioners for architectural coverings and treatments, such as blinds, curtains, and the like. More particularly, the present invention relates to a looped-cord tensioner that prevents operation of the architectural covering unless the tensioner is first mounted to a wall or other non-moveable structure. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many types of architectural coverings and treatments, such as Venetian blinds, cellular or pleated shades, and variants of these (herein represented without restriction merely by “shades”) utilize an actuator known as a looped-cord or continuous looped-cord. Such cords are distinct from the basic pull cord style shades in that the looped-cord does not connect directly to the shade material, but rather engages a clutch on a rotating shaft in a headrail of the shade. Movement of the looped-cord in a first direction operates that clutch to accumulate shade material when opening, and movement of the looped-cord in a second direction lets out shade material. The looped-cord may be made at different lengths than the shade and may be configured to make multiple circulations during opening and closing of the shade. The benefits of a looped-cord system versus a standard pull cord system are that the exposed looped-cord remains at a constant length whether the shade is open or closed (avoiding the problem of stowing the long exposed pull cord when the shade is opened). Moreover, a looped-cord system also provides a mechanical advantage to raise relatively large, heavy shades with reasonable cord forces. 
         [0003]    However, looped-cords also have a significant disadvantage. Generally, looped-cords hang freely along a side of the shade they are used to operate. Many looped-cords are long enough that they reach the floor and are easily grasped by babies and young children as a potential play toy. Rather than a play toy, however, a dangling looped-cord has proved to be a health hazard to babies and young children. In recent years, cases of death or injury have been documented in which a person, typically a baby or a small child, has become entangled in the looped-cord and has choked or become asphyxiated when the looped-cord became wrapped around their neck and constricted their airways. 
         [0004]    In an effort to alleviate this health risk, current safety regulations require that looped-cord style shades be supplied with a device commonly known as a tensioner. A tensioner typically includes a two-piece housing with a through passage for a looped-cord and a provision for attaching the tensioner to a wall or other fixed structure. The tensioner is designed to be mounted to a wall or other non-movable structure at some distance away from the clutch. The tensioner allows the looped-cord to be pulled taut during the mounting process, at rest, and during operation, so that it may be difficult to spread the two sides of the looped-cord apart enough for it to pass over a child&#39;s head, thereby preventing injury and possibly death. However, because a taut looped-cord is difficult to operate, a number of tensioners are installed incorrectly. Specifically, some tensioners are installed with a dangerous amount of slack in the looped-cord and some tensioners may not be installed at all. 
         [0005]    To minimize the limitations of known tensioners, improved versions of the aforementioned tensioner design have been developed. One design includes a tensioning spring between a cord contacting member and a tensioner mounting body. This improved design allows the tensioner to be mounted with the looped-cords fully taut and the tensioning spring partially loaded. The pre-loaded spring holds the looped-cord taut while not in operation, thus preventing a baby or young child from spreading the looped-cord wide enough to pass their head through. During operation of the looped-cord, an adult operating the looped-cord will be able to overcome the remainder of the spring loading and easily pull the looped-cord to open or close the shade. However, even this improved tensioner design has not fully addressed the safety concerns associated with the looped-cord because there is no requirement that the tensioner be installed to effectively operate the shade. The end user may elect not to mount the tensioner to the wall or other non-moveable structure and instead use the tensioner as a weight at the bottom of the looped-cord. Although new tensioner designs include safety improvements, if the tensioner is not mounted to the wall, as discussed above, it will not prevent the opening of the looped-cord to a dangerous width. 
         [0006]    Therefore, a need exists for a tensioner that is prevented from operating to open and close a shade unless it is mounted to a wall or other non-moveable structure. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    A looped-cord tensioner for an architectural covering including a housing adapted for attachment to a looped-cord, an abutment member positioned within the housing, a slide member positioned within the housing, and at least one biasing element having a first end and a second end. One of the slide member and the abutment member is adapted to engage the second end of the biasing element and the first end of said biasing element is adapted to engage the housing such that one of the slide member and the abutment member is moveably positioned in the housing so as to bias one of the slide member and the abutment member toward engagement with the looped-cord such that the looped-cord is normally non-movably sandwiched between the slide member and the abutment member prior to installation of the looped-cord tensioner. One of the slide member and the housing is adapted to be fixedly installed to a non-movable structure adjacent the architectural covering such that one of the slide member and the abutment member is disengaged from the looped-cord and the looped-cord is free to moveably pass through the housing following proper installation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims, and drawings, of which the following is a brief description; 
           [0009]      FIG. 1  is a perspective view of a looped-cord window treatment that includes an improved looped-cord tensioner according to an embodiment of the present invention; 
           [0010]      FIGS. 2A and 2B  are side views of male and female portions, respectively, of a looped-cord tensioner according to an embodiment of the present invention; 
           [0011]      FIGS. 3A and 3B  are perspective views of a looped-cord tensioner according to another embodiment of the present invention;  100   FIG. 4  is side view of a looped-cord tensioner according to another embodiment of the present invention; 
           [0012]      FIG. 5  is side view of a looped-cord tensioner according to another embodiment of the present invention; and 
           [0013]      FIGS. 6A and 6B  are a perspective view and top view, respectively, of a looped-cord tensioner according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring now to  FIG. 1 , there is shown a partial view of a looped-cord window treatment  8  that includes a shade  10 , a headrail  12 , a bottom rail  14 , and at least one lift cord  16 . Headrail  12  is mounted above a window or door unit and shade  10  is attached to headrail  12  and allowed to bang vertically to cover the window or door unit. Bottom rail  14  is attached to the bottom of shade  10  to add weight to shade  10 , which ensures that shade  10  may be lowered quickly, covers the window or door unit properly, and is not easily blown around by the wind if the window or door unit is open. Bottom rail  14  also serves as an attachment point for lift cord  16  so that shade  10  may be raised and lowered. Lift cord  16  may also attach at one or more points along shade  10 , however, the major pulling force is on the bottom rail  16  during raising and lowering of shade  10  so that shade  10  is not damaged by the pulling forces of lift cord  16 . 
         [0015]    Headrail  12  includes a rotating shaft  18  having a clutch  20 . Clutch  20  includes a looped-cord  22  that is used in operating clutch  20  to raise and lower shade  10 . Lift cord  16  is attached to rotating shaft  18  and is wound about rotating shaft  18  during the raising of shade  10  and unwound during the lowering of shade  10 , Looped-cord  22  does not connect directly to shade  10 , but rather drives clutch  20 , which in turn rotates shaft  18  and either winds lift cord  16  on shaft  18  to raise shade  10  or unwinds lift cord  16  from shaft  18  to lower shade  10 . Looped-cord  22  may be made at different lengths than shade  10  and may be configured to make multiple circulations during operation of clutch  20 . A looped-cord tensioner  24  is mounted to a wall or other non-movable structure adjacent to shade  10 . Among other benefits, the window treatment design shown in  FIG. 1  includes a constant length of exposed looped-cord  22  (avoiding the problem of stowing a long exposed cord found in pull-cord style window treatment designs while the treatment is open). Moreover, loop-cord  22  and clutch  20  cooperatively provide a mechanical advantage to raise relatively large, heavy shades with reasonable looped-cord  22  forces. 
         [0016]    With reference to  FIGS. 2A and 2B , an embodiment of tensioner  24  will be described in detail. In the illustrated embodiment, tensioner  24  includes a male member  26 , a female member  28 , a sliding lock  30 , and a biasing element  32 . Male member  26  includes a first surface  34  having a wall  36  extending outward from and generally perpendicular to first surface  34 . Wall  36  surrounds three sides of first surface  34  and includes a shoulder  38  for accepting female member  28 . A top edge  40  of wall  36  includes locking tabs  42  (also see  42 ′ in  FIGS. 3A and 3B ) for securing male member  26  to female member  28 . 
         [0017]    In an embodiment an interior portion  44  of first surface  34  includes an abutment member  46 . In this particular embodiment, abutment member  46  is an outer cylinder having slots  72  for engaging locking tabs  48  of an inner cylinder  50  on female member  28  (also see  72 ′ and  48 ′ in  FIGS. 3A and 3B ), Interior portion  44  further includes at least one support wall  52  for supporting female member  28  during operation of tensioner  24 . Interior portion  44  also includes a slot  54  for accepting a portion of lock  30  to allow lock  30  to slide within male member  26 . The portion of lock  30  that enters slot  54  is a boss  31  that extends from either relatively flat surface of lock  30  and includes a hole  56  to accept a fastener, such as a screw, so that tensioner  24  may be mounted to a wall or other non-moveable structure. Lock  30  also includes a first engagement surface  58  for engaging a first end of biasing element  32 , which is shown as being a spring. Interior portion  44  may also include at least one post  60  having a second engagement surface  61  for engaging a second end of biasing element  32 . Alternatively, post  60  may be omitted and the second end of biasing element  32  may engage an interior surface of wall  36 . 
         [0018]    As shown in  FIG. 2B , female member  28  includes a second surface  62  having a wall  64  extending outward from and generally perpendicular to second surface  62 . Wall  64  surrounds three sides of second surface  62  and includes an edge  66  that abuts shoulder  28  of male member  24  when tensioner  24  is assembled. Wall  64  also includes depressions  68  for accepting locking tabs  42  to secure female member  28  to male member  26 . An interior portion  70  of second surface  62  includes inner cylinder  50  sized to be inserted into outer cylinder  46  as male member  26  is assembled to female member  28 . Interior portion  70  also includes a slot  74  for accepting boss  31  of lock  30  to allow lock  30  to slide within female member  26 . 
         [0019]    In an embodiment of the present invention, lock  30  may be generally rectangular in shape with hole  56  passing though boss  31  to accept the fastener. Lock  30  may also include a face  76  at an edge  78  that engages and locks looped-cord  22  against movement when lock  30  is not in tension (i.e. tensioner  24  is not secured to a wall or other non-moveable structure by lock  30 ). Face  76  of lock  30  may be of any general shape, provided face  76  engages and locks looped-cord  22  and prevents operation of looped-cord  22  until tensioner  24  is properly mounted. Face  76  may be serrated, saw-toothed, cleated or have some other means of increasing the friction between the face/looped-cord  76 / 22  interface to prevent movement of looped-cord  22  within tensioner  24  until tensioner  24  is properly mounted. As discussed boss  31  surrounds hole  56  that passes though lock  30 . Boss  31  is sized to fit into slots  54  and  74 , such that tensioner  24  permits lock  30  to be moved within slots  54  and  74  and allows the disengagement of face  76  from looped-cord  22  when lock  30  is moved out of engagement with looped-cord  22 . Components of tensioner  24  may be manufactured from any metallic or polymeric material, such as aluminum, steel, nylon, and the like. 
         [0020]    In an embodiment of the present invention, tensioner  24  is assembled in the following manner. First, looped-cord  22  is placed onto outer cylinder  46  of male member  26 . Next, lock  30  is set in slot  54  of male member  26  such that boss  31  extends through slot  54  and biasing element  32  is positioned between lock  30  and post  60  at first and second engagement points  58  and  61 , respectively. Face  76  of lock  30  is now in engagement with looped-cord  22  to prevent its movement about cylinder  46 . Female member  28  is then press-fit onto male member  26  so that locking tabs  42  engage depressions  68  and locking tabs  48  of inner cylinder  50  engage slots  72  of outer cylinder  46  forming a resilient interference fit. Boss  31  now extends through slot  74  of female member  28  as well. As stated above, lock  30  is positioned such that face  76  engages and locks looped-cord  22  and prevents movement of looped-cord  22  within tensioner  24 . 
         [0021]    To install tensioner  24  and operate shade  10 ; shade  10  should first be installed in a location determined by the user, usually over a window unit or other architectural opening. After installation of shade  10 , tensioner  24  is located and secured to a wall or other non-movable structure adjacent shade  10  in the following manner. Tensioner  24  is located on the wall such that all the slack has been removed from looped-cord  22 . Once tensioner  24  has been positioned on the wall such that looped-cord  22  is taut, lock  30  may be slid downward through slots  54  and  74 , compressing biasing element  32 , such that face  76  will disengage and unlock looped-cord  22 . Thereafter, a fastener should be driven through hole  56  of lock  30  and into a wall to position lock  30  in a manner that does not inhibit the movement of looped-cord  22  around outer cylinder  46 . Positioning of lock  30  in this manner allows looped-cord  22  to enter and exit tensioner  24  freely in order to make multiple circulations so that shade  10  may be raised and lowered. Only by properly installing tensioner  24 , which compresses its biasing element  32 , thereby unlocking looped-cord  22 , may looped-cord  22  travel freely through tensioner  24  to permit operation of shade  10 , Following installation, biasing element  32  continues to exert a downward force on post  60  and members  26  and  28 , thereby maintaining the desired tautness in looped-cord  22 . 
         [0022]    Now referring to  FIGS. 3A and 3B , in another embodiment of tensioner  24  is shown (denoted as  24 ′), which includes a sliding lock  30 ′ that is generally circular in shape and has two arms  81  that serve as attachment points for biasing elements  32 ′. In this particular embodiment, tensioner  24 ′ includes a pair of biasing elements  32 ′, such as tensioner springs. Each biasing element  32 ′ is attached to a point on arm  81  and to posts  60 ′ of male member  26 ′. Face  76 ′ of lock  30 ′ may be serrated or cleated as in the prior embodiment. Assembly and operation of tensioner  24 ′ is substantially similar to that described above with respect to tensioner  24  and, therefore, will not be described in further detail here. 
         [0023]    In another embodiment shown in  FIG. 4 , a tensioner  24 ″ is provided that includes the attachments in reverse. Looped-cord  22  may be attached to tensioner  24 ″ at abutment member  46 ″ that is allowed to slide within tensioner  24 ″. In this particular embodiment, the attaching point for tensioner  24 ″ to the wall or other non-movable structure is a hole  90  through the member  26 ″ and female member (not shown) of tensioner  24 ″. Abutment member  46 ″ is allowed to slide freely in slot  54 ″ and is attached to male member  26 ″ by biasing element  33 . In this particular embodiment, sliding lock  30 ″ is configured to be non-movable within tensioner  24 ″ and may include a face  76  to engage and lock looped-cord  22  as previously described. The assembly and operation of tensioner  24 ″ is as described above as well. These embodiments are illustrative of a number of different configurations of tensioner  24 , yet the underlying operation of the invention is the same, preventing the operation of looped-cord  22  in shade  10  unless tensioner  24  is properly mounted to an adjacent wall or other non-movable structure. 
         [0024]    In another embodiment shown in  FIG. 5 , a tensioner  24 ′″ is provided that includes abutment member  46 ″ that is allowed to slide freely in slot  54 ′″ as well as the slot in the corresponding female member (not shown). Looped-cord  22  may be looped around abutment member  46 ″ as discussed in previous embodiments. Sliding lock  30  is employed as discussed above with the descriptions relating to  FIGS. 2A and 2B . Face  76  of sliding lock  30  engages and locks looped-cord  22 , also discussed above in relation to the embodiments illustrated in  FIGS. 2A and 2B . In this particular embodiment, both abutment member  46 ″ and sliding lock  30  are moveable within tensioner  24 ′″. The assembly and operation of tensioner  24 ′″ is as described in the previous embodiments above. Again, each of these embodiments are illustrative of a number of different configurations of tensioner  24 , yet the underlying operation of the invention is the same—preventing operation of looped-cord  22  in shade  10  unless tensioner  24  is properly mounted to an adjacent wall or other non-movable structure, 
         [0025]    The above embodiments illustrate tensioners  24 ,  24 ′,  24 ″, and  24 ′″ that may require looped-cord  22  to be included in the assembly of tensioner  24  prior to operation. In another embodiment of the present invention shown in  FIGS. 6A and 613 , a tensioner  240  is provided that allows looped-cord  22  to be inserted into the tensioner after complete assembly of tensioner  240 , and thereafter prevent removal of looped-cord  22  from tensioner  240 . In this particular embodiment, abutment member is a pair of tabs  82  and  84 . Inner and outer cylinders  46 ,  50  of tensioner  24  have been replaced with tabs  82  and  84 . A first tab  82  extends generally perpendicular from interior portion  440  of male member  260  near an opening where looped-cord  22  enters tensioner  240 . A second tab  84  extends generally perpendicular from interior portion  700  of female member  280  near the opening where looped-cord  22  enters tensioner  240 . Each tab  82 ,  84  extends out a length from interior portion  440 ,  700  sufficient to form gaps  86  and  88  between tabs  82 ,  84  and interior portions  440 ,  700  when tensioner  240  is fully assembled. In this manner, looped-cord  22  may be forced through gaps  86  and  88  (by flexing member halves  26  and  28 ) so that tensioner  240  can be attached to looped-cord  22 . Both tabs  82  and  84  have curved surfaces for interfacing with looped-cord  22  so that looped-cord  22  is not damaged as looped-cord  22  rubs against tabs  82 ,  84  during operation of shade  10 . Also, cord  22  may not be easily removed from tensioner  240  without forcibly prying apart members  260  and  280  or destroying tabs  82  and  84 . Tensioner  240  is then mounted to the wall in the same manner as described above to disengage face  76  from looped-cord  22  to allow for raising and lowering of shade  10 . 
         [0026]    As will be appreciated, the present invention may be used with any number of different window treatments including cellular shades, Venetian blinds, other pleated shades, and the like, which employ looped cords for opening and closing the window treatment. Although the preferred embodiment is described and shown for use with window treatments, it is important to note, however, that the present invention is not so limited and may be used with any architectural covering that requires a looped-cord for operation. 
         [0027]    The present invention has been particularly shown and described with reference to the foregoing embodiments, which are merely illustrative of the best modes for carrying out the invention. It should be understood by those skilled in the art that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention without departing from the spirit and scope of the invention as defined in the following claims. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. This description of the invention should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. Moreover, the foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.