Patent Publication Number: US-2003221800-A1

Title: Louver blinds

Description:
BACKGROUND  
       [0001] Field of the Invention  
       [0002] 1. This invention relates to devices for controlling light passing through an architectural opening. It particularly relates to louver shades or blinds for windows, doors, and room dividers.  
       [0003] 2. State of the Art  
       [0004] Conventional horizontal blinds have a plurality of louvers suspended on rungs of ladder-type structure. At least two ladder tracks are suspended from a headrail structure, which typically is capable of distorting the ladder apertures to rotate the louver elements. One or more additional ladder tracks are included in wider blinds to limit the length of unsupported louver between the tracks. Typical louvers in such conventional blinds have two or more spaced apart routing holes, each of which receives a (typically single strand) control line, or lift-cord, to provide elevation control of the bottom of the blind. The control line also serves to maintain an alignment of all the louvers, and prevents an individual louver from migrating out of the array of louvers forming the blind. The routing hole unavoidably “leaks” some light in a vertically disposed and intermittent line.  
       [0005] To overcome the annoying light-leaking limitation, “privacy blinds” can be made that have no mid-span routing hole. Such privacy blinds dispose one or more elevation control lines at front and/or rear edges of the louver at locations typically corresponding to the routing holes of conventional blinds. Alignment of the privacy louver elements typically is maintained by a notch in one edge of the louver that is disposed to interface with a suspension track. Engagement of the notch and track prevents side-to-side movement of the louver. Alternatively, in conventional-type louvers, a narrow band of fabric or other flexible material is sometimes placed top-to-bottom of the blind, in front of the routing hole(s), to add an additional blocking surface.  
       [0006] Conventional blinds are considered by some consumers to be boring or unappealing in that they have a straight bar appearance. Woodring&#39;s U.S. patent application Ser. No. 09/765,512, titled “DECORATIVE VENETIAN BLINDS” was filed Jan. 19, 2001, and discloses horizontal blinds with louvers having one edge of conventional horizontal louver elements being shaped to provide multiple shallow scallops, or other patterns, to change the appearance of the blinds from inside a room. The conventional louver elements taught in the &#39;512 application each have the annoying route holes for lift-cords, which unavoidably leak light in a vertical interrupted line. No suggestion is made in the &#39;512 application to form decorative edge structure operable to maintain alignment of a plurality of louver elements.  
       [0007] Design patents Des. 361,099; Des. 362,978; Des. 363,386; Des. 363,387; and Des. 369,265, issued to Potts, and Des. 407,935 and Des. 407,936, issued to Spektor, illustrate multiple vertical louver elements having both edges being shaped in various decorative configurations. Neither of Potts nor Spektor disclose structure to suspend louver elements in a horizontal configuration and maintain an alignment of the louvers. Litecki, in Des. 401,097 and Des. 401,098 discloses horizontal blinds having louvers with nonlinear edges. However, Litecki discloses louvers having an otherwise conventional design, with each louver having a pair of route holes in which to receive lift-cords.  
       [0008] Attempts have been made in certain window coverings to provide for a variation in form and pattern of transmitted light and shadow cast into a room. Variable aperture sizes may be created by a device constructed according to teachings of de Kimpe et al. in U.S. Pat. No. 6,161,607. de Kimpe et al. disclose a blind having a flexible sheet of covering material that can be tensioned to open a plurality of apertures. However, a size of the aperture openings is necessarily limited by the extent to which a covering material may be stretched in tension, among other limiting factors.  
       [0009] An improved decorative privacy-type louver for horizontal blinds that is capable of interfacing with suspension structure to maintain alignment of the louvers in a blind would be an improvement in the art of window coverings. A horizontal blind capable of causing a significant variation in form and pattern of transmitted light and shadow cast into a room would also be an improvement.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010] The present invention provides an improved louver apparatus operable to regulate transmission of light through an architectural opening. Such apparatus typically includes a plurality of louvers. Each of the louvers has a blocking portion and an interface portion, and can be disposed in combination substantially to cover an area to control light passing perpendicularly through the area. The apparatus generally includes a mechanism adapted to hold the louvers at their interface portion and operable to rotate the louvers between a first, a second, and a third orientation. At the first orientation, the blocking portion of the louvers blocks perpendicular transmission of light through the area. At the second orientation, at least one aperture is formed in the blocking portion between two adjacent louvers, and is disposed spaced apart from an interface portion. The aperture permits perpendicular transmission of light through a part of the blocking portion of two adjacent louvers. At the third orientation, a slot, permitting transmission of light perpendicular to the area, is formed between adjacent louvers.  
       [0011] Individual louvers each include first and second edges and, at the first orientation, a length of a first edge of a first louver overlaps a length of a second edge of an adjacent and complimentary louver to block perpendicular light transmission through the blocking portion or portions. The first edge of the first louver element has a nonlinear portion that is shaped, in combination with the second edge of the adjacent and complimentary louver, to form at least one aperture when the louvers are rotated to the second orientation. In certain embodiments of the invention, at the second orientation, a plurality of apertures are formed between adjacent louvers, and are spaced apart in the blocking portion. One workable louver&#39;s first edge has an undulating portion operable to form the apertures. A second workable louver includes an edge with a scalloped portion. A third workable louver includes an edge with an offset block portion. Certain embodiments of the invention may have their louvers arranged for generally vertical dependency below the holding mechanism. Other embodiments of the invention may have their louvers arranged for generally horizontal deployment below the holding mechanism.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012] In the drawings, which illustrate what are currently considered to be the best modes for carrying out the invention:  
     [0013]FIG. 1 is a front view in perspective of a suspended prior art horizontal blind;  1121  FIG. 2 is a rear view in perspective of one embodiment of a prior art horizontal privacy blind;  
     [0014]FIG. 3 is a front view in perspective of a horizontal privacy blind according to the invention;  
     [0015]FIG. 4 is a plan view of a prior art conventional louver element;  
     [0016]FIG. 5 is a plan view of a prior art privacy louver element;  1161  FIG. 6 is a plan view of a preferred privacy louver element according to the invention;  
     [0017]FIG. 7 is a plan view of alternative louver element construction according to the invention;  
     [0018]FIG. 8 is a plan view of additional alternative louver element construction according to the invention;  
     [0019]FIG. 9 is a side view of a portion of ladder support structure for a horizontal blind;  
     [0020]FIG. 10 is a side view of a portion of a horizontal blind according to the invention in a fully open position;  
     [0021]FIG. 11 is a side view of a portion of a horizontal blind according to the invention in a partially open position;  1221  FIG. 12 is a side view of a portion of a horizontal blind according to the invention in a substantially closed position;  
     [0022]FIG. 13 is a front view of a portion of a preferred horizontal blind in a fully open position;  
     [0023]FIG. 14 is a front view of a portion of a preferred horizontal blind in a partially open position;  1251  FIG. 15 is a front view of a portion of a preferred horizontal blind in a substantially closed position;  
     [0024]FIG. 16 is a front view of a preferred vertical blind; and  
     [0025]FIG. 17 is a view in perspective of an alternate louver for a vertical blind. 
    
    
     DETAILED DESCRIPTION  
     [0026] A conventional horizontal blind, generally indicated at  100 , is illustrated in FIG. 1. Blind  100  includes a plurality of louver elements  101 , suspended in approximately parallel alignment between a head rail  102  and a ballast element  104 . Left lift-cord  106  and right lift-cord  107  are typically user operated to raise and lower the ballast element  104  of the blind  100  by pulling or releasing knobs  108 . Lift-cords  106  and  107 , illustrated in FIG. 1, pass through apertures, or route holes  109  disposed in each louver element  101 . Such lift-cords  106 ,  107  are also operable to maintain an alignment of the plurality of louvers  101 .  
     [0027] Apertures  109  are sized larger than a cross-section through lift cords  106  and  107  to permit smooth action in raising and lowering the bottom ballast element  104  and individual louvers  101 . Therefore, apertures  109  unavoidably produce an unoccluded space in each louver  101  through which light will pass, or leak, when the louvers  101  are rotated to a closed orientation. A blind  100  typically is closed by rotating control handle  110 , which causes a corresponding distortion of ladder-type suspension tracks  112  and  114  that orients the plurality of louvers  101  in overlapping proximity.  
     [0028] One solution to avoid the presence of such apertures  109  is illustrated by a privacy blind, generally indicated at  120  in FIG. 2. A plurality of privacy-type louvers  124  replace the conventional louvers  101  to create a privacy blind  120 . Each louver  124  typically carries interface structure, generally indicated at  126 , to retain individual louvers  124  in alignment with ladder structure  112  and  114 . In the embodiment illustrated in FIG. 2, the interface structure is arranged as a plurality of notches  128  disposed on the outside edge of each louver  124 . Blinds  120  preferably carry such interface structure  126  disposed on the outside edge to present an uninterrupted linear louver edge on the inside (visible from the room) surface of the blind  120 .  
     [0029] A privacy blind manufactured by Fashion Tech, of Portland, Oreg., has small, substantially rectangular notches formed by a saw cutting operation on the outside edge of louver elements. The Fashion Tech privacy louver elements have louver widths in correspondence with conventional suspension ladder structure. That is, a 2 inch privacy louver is suspended in a ladder structure sized to hold 2 inch conventional louvers. The Fashion Tech alignment notch does not cause a decrease in suspension ladder size.  
     [0030] In privacy blinds, such as blind  120 , a single lift-cord  106  is typically replaced by a pair of lift cords disposed one inside, and one outside of the louver  124 , to avoid the requirement for an aperture  109  in a louver  124 . Such paired lift-cords in a privacy blind  120  are typically provided at locations corresponding to lift-cord locations for a conventional blind, such as blind  100 . A single lift-cord disposed at an edge is also operable, but trends to cause a certain rotation of the louver elements when the single lift cord is actuated.  
     [0031] One embodiment of the invention, generally indicated at  130  in FIG. 3, provides multiple louver elements  135  having a decorative edge generally indicated at  137 . Edge  137  of each louver  135  functions to maintain an alignment of the louver  135  in ladder tracks  112  and  114 . It is within contemplation to include a mix of both decorative-edged and straight-edged louvers in a blind  130 . Blinds incorporating one or more louvers  135  offer a pleasing visual appearance from the inside of the room. Furthermore, such blinds  130  also offer light transmission options not obtainable in conventional blinds. As will be more fully discussed below, the privacy louvers  135  and decorative edge  137  permits formation of variable-sized apertures through which light may pass, in addition to a substantially rectangular opening similar to that produced between open conventional louvers. Of course as with conventional blinds, blinds constructed according to the invention may be disposed in front of a window  138  as illustrated, or hung inside the window  138  opening.  
     [0032] A plurality of louver elements, each structured for suspension in ladder structure of the same 2-inch nominal size and generally indicated at W, are illustrated in FIGS. 4 through 8. While louvers having a nominal 2-inch suspension size are illustrated for the convenience of relative comparison, the invention is operable in louvers having other nominal suspension sizes as well, including 1-inch and larger.  
     [0033]FIG. 4 illustrates a conventional louver element, generally indicated at  140 . Louver  140  has a pair of routing holes  142  disposed at suspension portions  144 . Louver  140  also provides a plurality of blocking portions, including left and right blocking portions  146  and  147  respectively. A single illustrated center blocking portion  148  is disposed between two suspension portions  144 . In certain longer embodiments of a louver, additional center blocking portions  148  may be disposed between additional suspension portions  144 .  
     [0034] Privacy-type horizontal louvers are illustrated in FIGS.  5 - 8 . Such louvers also have suspension portions  144  and blocking portions  146 - 148 . The prior art louver, generally indicated at  150  in FIG. 5, has a linear inside edge  152 . Notches, generally indicated at  154 , are cut into the width W of the louver  150  that is supported at suspension portions  144 . Such notches  154  operate to maintain an alignment of a plurality of louvers  150  in a blind because the ladder suspension structure can sag slightly to cause an interference with the notches  154 .  
     [0035] An exemplary, and currently preferred, louver according to the present invention is generally indicated at  160  in FIG. 6. Louver  160  has a nonlinear and decorative inside edge  162 . While outside edge  164  is illustrated as being linear, it is within contemplation also for outside edge  164  to be nonlinear. It is further within contemplation for edge  164  to include one or more notches, such as a notch  154  illustrated in FIG. 5. Decorative edge structure in a louver according to the present invention, generally indicated at  167 , is formed from louver material extending beyond the nominal louver suspended width W. An interface portion, generally indicated at  168 , interfaces with suspension structure and helps maintain an alignment of a plurality of suspended louvers  160 .  
     [0036] Louvers according to the invention may be described as having an inside edge  162  and an outside edge  164  between left end  165  and right end  166 . The edges  162 ,  164  and ends  165 ,  166  circumscribe blocking portions  146 - 148  and suspension portions  144 . Left and right end portions L l  and L r  preferably are symmetric with respect to a pattern formed on inside edge  162 . The pattern preferably has a repeating size based on either a multiple or fraction of L l  and L r  to enable trimming the blinds to fit a particular window. In certain embodiments of the invention, it is preferred to premanufacture a blind with both L l  and L r  having a length of about ½ the repeating pattern length L p . For many blinds, L l  and L r  are between about 3 and 7 inches, with a corresponding L p  ranging between about 3 and 14 inches. Certain preferred louvers have a pattern length L p  of about 7 inches. Certain preferred louvers for suspension in 2-inch ladder structure have an L p  of about 7 inches and an approximately circular arc pattern, such as illustrated in FIG. 6. One desirable such pattern includes arcuate sections joined together at cusp-like intersections.  
     [0037]FIGS. 7 and 8 illustrate louver elements having alternative decorative nonlinear inside edge structure, generally indicated at  172 ,  174 ,  182 , and  184  respectively. Again, the decorative edge is formed from louver material extending beyond the supported width W. The decorative edge structure of the invention protrudes as a cantilevered lip that increases an overlap with the adjacent lower louver compared to a conventional louver, such as louver  140 , or even a privacy-type louver such as louver  150 . Accordingly, louver elements constructed according to the invention will form an overlapped blocking portion  148  in combination with an adjacent louver at a lesser rotation from a horizontal (or fully open) position compared to prior art louvers.  
     [0038] As used in this disclosure, a blocking portion  146 - 148  is separate and distinct from a suspension portion  144 . A blocking portion  146 - 148  is defined as the overlappable portion formable between adjacent louver elements to form a barrier to vision perpendicular to and through the blind device. A louver&#39;s total length is the sum of the lengths of the blocking and suspension portions. Certain louvers (e.g. vertical blinds), typically will have one suspension portion  144 , and one blocking portion. Other louvers (e.g. horizontal blinds), may have multiple blocking portions  146 - 148  and two or more suspension portions  144 . In certain suspension systems, the suspension portion  144  can also function to overlap to provide a complete light-blocking overlap along the entire length of the louver. However, the suspension portion  144  remains distinguishable over a blocking portion  146 - 148 .  
     [0039] A suspension portion  144  is defined as that portion of the louver adapted to interface with the suspension element (or elements) of the suspension mechanism. A suspension portion  144  generally has a length that is equal to a diameter or width of suspension structure, such as a rung of a suspension track, plus an additional length for clearance. Suspension portions  144  desirably provide alignment structure operable to form a structural interference with the suspension element(s) to resist movement of a louver from alignment with other louvers in a blind. One exemplary suspension portion  144  is created at a louver section having a reduced width W compared to the maximum louver width. Such a reduced width W typically is sized in accordance with the length of suspension elements, such as a rung  192  of a conventional ladder-type louver suspension system  190  in a horizontal blind. Suitably shaped louver elements, according to the invention, offer a dimensional change in width at, or near, an interface portion  168  operable to form a structural interference with suspension structure  190 . An interface portion, such as  168  in FIG. 6, typically includes an edge portion of at least one edge at a suspension portion  144  location.  
     [0040] In general, suspension structure  190  relates to any structure operable to control the orientation or location of a louver relative to mounting structure of a blind. The phrase “whereby to maintain an alignment of a louver in a suspension structure” means that under normal use (e.g. suspended in front of a window), the louver elements are restrained from wandering out of alignment. A structural interference is created between louver edge structure and suspension structure to resist moving the individual louvers out of alignment. No routing hole is required, and therefore that annoying aperture is eliminated in embodiments of the invention.  
     [0041] With reference to FIG. 9, it should be noted that, in general, the louver elements according to the invention can be removed from a suspension ladder of at least certain horizontal blinds by orienting such louvers on a diagonal with respect to the louver suspension box  204  formed between two adjacent rungs  192  and front rail  205  and rear rail  206 . In fact, such louver positioning is utilized in the preferred assembly technique to manufacture blinds with the improved louvers according to the instant invention. However, during normal operation, the louvers are disposed in contact with a supporting rung  192 , and do not tip to a diagonal position with respect to the louver suspension box  204 .  
     [0042] Retaining interfaces  168  for privacy-type louvers are defined as structure carried by a louver and operable to maintain alignment of a louver with respect to suspension structure; typically ladder structure  190  in the case of horizontal blinds. Privacy-type louvers, such as illustrated in FIGS. 5 through 8, are defined as louvers without routing holes for lift-cords, and which leak light through nonoverlapped portions of a closed blind. For a privacy-type louver according to the instant invention, retaining interfaces  168  are formed strictly from the shape of at least one louver edge, at a location in proximity to suspension structure. In particular, no apertures are formed through the privacy-type louver in which to accommodate suspension structure such as elevation control cords. Any elevation control cords are disposed outboard of one or both edges of a privacy-type louver. In general, a ladder rail  205 ,  206  or rung  192  structurally interferes with a retaining interface of a privacy-type louver to resist migration of the louver away from an alignment with the ladder structure  190 .  1451  Ladder-type suspension tracks, such as generally indicated at  190  in FIG. 9, are commercially available having rungs  192  sized to accomodate louvers having 1, 1½, 2, and more recently, 2½ inch suspension widths. A privacy-type louver, according to the invention, can be manufactured by forming an appropriate edge shape in a louver having a maximum width about ½ inch larger than a rung size of the suspension track. That is, a louver with a maximum width of about 2½ inches desirably will have a nonlinear edge shaped to accomodate reception of the louver in a 2 inch ladder-type suspension track.  
     [0043] In general, oversizing the maximum louver width compared to the length of a suspension track rung  192  can help to create a desired interference between suspension structure of the track and interface structure  168  carried on one or more edges of the improved privacy-type louver. Furthermore, the oversized width of the improved louver permits formation of decorative edge structure in that extra width portion, while producing an overlap section between adjacent louvers at least equal in size to that overlap provided by conventional louvers sized for the same suspension track. Of course, an operable nonlinear edge shape may also undulate in some fashion beyond the extra width portion, partially to reduce a portion of the overlapped section between louvers corresponding to a conventional overlapped section. However, a closed blind desirably will have at least a certain amount of overlap between adjacent louvers.  
     [0044]FIGS. 10 through 12 illustrate perpendicular light, indicated at  200 , being variably obstructed by louver elements  202 . As ladder structure  190  is manipulated to distort a box  204  in which a louver  202  is supported, the louver elements  202  block increasing amounts of perpendicular light  200 .  
     [0045]FIGS. 13 through 15 illustrate a plurality of improved louvers  160  in various rotation orientations. FIG. 13 illustrates louvers  160  in a fully open rotation orientation, permitting passage of light  200  through a plurality of apertures or slots  208 . In FIG. 14, apertures  208  are subdivided to form a plurality of apertures  210 . Apertures  210  are formed by a portion of louvers  160  that overlap their adjacent below-positioned louver  160  at a lesser rotation angle than a conventional louver  101 . Apertures  210  are variable in size, with their size and conformation depending on rotation orientation of the louvers  160 . The variation in size of apertures  210  causes a corresponding beneficial variation in form and pattern of transmitted light and shadow cast into a room equipped with an embodiment of the invention. At least certain of apertures  210  are formed spaced apart from interface portions  168  at suspension locations  144 . FIG. 15 illustrates louvers  160  rotated to a third rotation orientation, which blocks passage of perpendicular light  200 .  
     [0046]FIG. 16 illustrates an embodiment of a vertical blind, generally indicated at  220 , having vertically disposed louver elements  222  constructed according to the present invention. FIG. 17 illustrates one construction of an alternative vertical louver element  224  according to the present invention. Louver  224  includes suspension portion  144  and a blocking portion  147 .  
     [0047] Louvers according to the present invention can be manufactured by stamping individual louvers from sheet stock, pultruding or forming from ribbon stock cut to length, and/or by cutting, routing, milling or performing some other machining operation to form a decorative edge structure. Materials from which louvers may be made can nonexclusively include plastic, metal, wood, and any other material suitable for use in a conventional louver.  
     [0048] While the invention has been described in particular with reference to certain illustrated embodiments, such is not intended to limit the scope of the invention. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.