WINDOW BLINDS

RELATED APPLICATION This application relates to Design Application Serial No. 07/395,096 filed August 16, 1989 entitled "Venetian Blind Slat".

BACKGROUND OF THE INVENTION

Window blinds comprise a plurality of horizontal slats suspended from a channel. The channel houses controls to permit selective tilting of the slats and/or the selective upward collapsing of the slats. The channel is attachable to mounting brackets which enable the window blinds to be mounted to appropiiate supports the top of a window.

A typical prior art window blind is illustrated in Fig. 1, and is identified by the numeral 10. The prior art blind 10 includes an array of horizontal slats 12 each of which comprises first and second opposed longitudinal ends 14 and 16 respectively. The slats 12 of the prior art blind 10 typically are formed from a thin metal material, but may also be formed from plastic, wood or other materials. Each slat 12 typically defines a width of between approximately one-half inch and approximately two inches and a length "a" corresponding to the width of the window to which the blinds 10 are to be mounted.

Each slat 12 of the prior art blind 10 include first and second lift cord apertures 18 and 20 extending therethrough in selected spaced relationship to the first and second ends 14 and 16 respectively. Thus, as shown in Fig. l, a vertical array of first lift cord apertures 18 and a vertical array of second lift cord apertures 20 are provided on the window blinds 10. The distance "b" between the first or second end 14 or 16 of each slat 12

and the respective first or second lift cord aperture 18 or 20 generally will be a function of the overall length "a" of each slat. On the typical window blind 10, the length "b" defining the distance between the lift cord apertures 18 or 20 and the associated ends 14 or 16 of each slat 12 will be about 20-25 percent of the overall length "a" of each slat 12. Window blinds intended for very wide windows may be provided with more than two lift cord apertures therethrough to provide adequate gravitational support for the thin slats as explained herein.

The lift cord apertures, 18, 20 of each slat 12 are of generally elongated configuration, with the longitudinal axis of each lift cord aperture 18, 20 extending generally orthogonal to the longitudinal axis of the respective slat 12. The length of each lift cord aperture, 18, 20 on the prior art slats 12 generally will be at least approximately one-half of the overall width of the associates slats 12. The prior art blinds 10 further comprise a channel 22 and a bottom rail 24. The channel 22 houses a tilt rod 26 which is rotatably mountable therein. The rotation of the tilt rod 26 is controlled by a tilt control mechanism 28 which is operated by a tilt wand 30 or other known actuating means. First and second barrels 32 and 34 are fixedly mounted to the tilt rod 26 of the prior art blinds 10 to be generally in register with the first and second lift cord apertures 18 and 20 of the slats 12.

The prior art blinds 10 further include first and second lift cords 38 and 40 which are mounted to the bottom rail 24 of the prior art blinds 10 and extend through the respective first and second lift cord apertures 18 and 20 of the slats 12. The first and second lift cords 38 and 40 continue through the channel 22 of the prior art blinds 10 and through a lift cord control mechanism (not shown) mounted therein, the first and ^' second lift cords 38 and 40 are then suspended from the

channel 22 of the prior art window blinds 10 to facilitate the selective upward collapsing of the array of slats in the prior art blind.

The prior art window blinds 10 further include first and second ladders 42 and 44 which extend generally between the channel 22 and the rail 24, and generally in alignment with the respective first and second lift cord apertures 18 and 20. The first and second ladders 42 and 44 are substantially identical to one another and are formed respectively from first and second arrays of flexible material. More particularly, with reference to the first ladder 42, a pair of runner 46 and 48 are disposed respectively on opposite sides of the slats 12 in the prior art blinds 10. Transverse supports (not shown) are connected to and extend between the runners 46 and 48 at equally spaced locations therealong. The transverse supports serve to support each respective slat 12. For stability, the transverse supports of the ladder 42 are interlaced relative to the lift cord 38, such that adjacent transverse supports are disposed on opposite respective sides of the lift cord 38. The runners 46 and 48 extend into the channel 22 and are mounted to the barrel 32. The rotation of the tilt rod 26 and the barrel 32 generated by appropriate actuation of the tilt wand 30 will cause the runners 46 and 48 of the ladder 42 to shift relative to one another. This longitudinal shifting of the runners 46 and 48 of the ladder 42 changes the angular alignment of the transverse supports relative to the runners 46 and 48, and thereby alters the tilt of the slats 12 in the prior art blind 10. The ladder 44 is disposed similarly relative to the lift cord 40 and operates in the same manner as ladder 42.

The prior art blinds illustrated in Fig. 1 and described above are considered effective means for controlling the lighting and other environmental conditions in a room. I ^ever, attempts to improve window blinds continue to be made. In this regard, the lift cord

apertures are visually readily apparent from the room in which the blinds are mounted. Additionally, in many angular alignments, the lift cord apertures of the prior art blinds permit light to enter a room, thereby affecting the overall lighting or environmental control that could otherwise be achieved by the blinds. In particular, as noted above, the lift cord apertures 18 and 20 of the prior art blinds 10 extend longitudinally in a direction transverse to the longitudinal direction of the slats 12. Although each lift cord aperture 18, 20 is relatively short, the aligned vertical arrays of lift cord apertures 18, 20 become visually quite apparent and can permit a relatively broad vertical fanlike distribution of light to enter a room. This can significantly affect the overall visual appearance of the prior art blinds 10 and can significantly alter the intended lighting or environmental effect to be achieved by the blinds 10.

The aligned lift cord apertures 18, 20, lift cords 38, 40 and ladders 42, 44 were considered to be a necessary configuration for window blinds. In particular, conventional wisdom and years of practice have taught that the ladders 42 and 44 needed to be spaced a significant distance inwardly from the respective ends 14 and 16 of each slat 12 the prior art blind 10, and that the lift cords 38 and 40 had to be interlaced relative to the transverse supports of the ladders 42 and 44 to prevent individual slats 12 from shifting longitudinally relative to one another and to provide necessary gravitational support. This necessarily disposed the visually apparent arrays of lift cord apertures 18 and 20, lift cords 38 and 40 and ladder 42 and 44 at a central location on the blinds.

The above described construction of the prior art blinds 10 provide another disadvantage. In particular, the elongated lift cord apertures 18 and 20 extending transverse to the longitudinal direction of each prior art slat 12 created a point of significant weakness in each ^•

slat 12. As a result, the slats 12 could be permanently crimped at locations thereon in alignment with the lift cord apertures 18 and 20. This crimping would occur in response to deformations by a person intending to separate two adjacent slats 12 for cleaning or to look out the window.

In view of the above, it is an object of the sub" ict invention to provide window blinds that are visually more attractive. It is another object of the subject invention to provide window blinds that enable more accurate control of the lighting and other environmental conditions in a room.

It is an additional object of the subject invention to provide window blinds that are stronger and less likely to be permanently crimped at central locations therealong. It is a further object of the subject invention is to provide window blinds that are substantially free of apertures at central location thereon.

SUMMARY OF THE INVENTION The subject invention is directed to window blinds comprising an array of horizontal slats which may be suspended from a channel or other support means. The slats are suspended by flexible tilt control ladders each of which comprises a pair of longitudinally extending runners and a plurality of transverse supports extending between the runners. As in the prior art blinds, each transverse support may be disposed to support a portion of a single slat in the array. The runners of each ladder extend upwardly from the slats and are mounted to control means which may be disposed in the channel. The control means may comprise an elongated tilt rod to which the runners of each ladder are m anted. The control means in the channel may further comprise a tilt control mechanism and a lift control mechanism. The window blinds of the subject invention further comprise lift cords which extend from the lift control mechanism in the channel through the

respective blinds and into secure engagement with a bottom rail of the window blinds.

Unlike the window blinds of the prior art, the lift cords of the subject window blinds are not aligned with the ladders thereof. Rather, the lift cords of the window blinds of the subject invention are disposed in very close proximity to the respective opposed ends of the blinds. More particularly, each slat of the blind comprises a pair of lift cord apertures formed therethrough in very close proximity to the respective ends of the slats. These portions of the blind are visually less obtrusive and often are blocked from direct exposure to light and/or direct vision by portions of the window frame or by decorative window adornments, such as curtains, drapes or the like.

As noted above, however, the support and tilt control ladders of window blinds must be spaced significant distances inwardly from the opposed ends of the blinds to ensure proper support for the slats. Thus, the tilt control and support ladders of the subject window blinds are disposed at selected locations inwardly from the opposed ends of each slat and in spaced relationship to the lift cord apertures. To prevent longitudinal sliding of the slats relative to the tilt control and support ladders, each slat of the subject window blinds may be provided with means for engaging at least one runner of the tilt control and support ladders. For example, each slat may comprise at least one notch formed in an edge region thereof for engaging the runners of the tilt control and support ladders. The engagement of the runner in the notch of the tilt control and support ladders will positively prevent shifting of the slats relative to the ladders. In certain embodiments, each slat will be provided with a pair of opposed notches for engaging both runners in a tilt control and support ladder.

Additionally, each slat may be provided with a plurality of pairs of notches corresponding in number and location

to the number of tilt control and support ladders in the window blind. Thus, a blind intended for fairly narrow windows may be provided with two tilt control and support ladders and each slat of the window blinds will be provided with two pairs of notches for engaging the ladders. On window blinds intended for wider windows, three or more tilt control and support ladders may be provided. In these embodiments each slat of the window blind may be provided with three or more pairs of notches for engaging the runners of the respective tilt control and support ladders.

As noted above, the channel of window blinds typically is mounted to an appropriate supporting structure on a window by mounting brackets. The typical installation procedure is to first mount the brackets to the supporting structure and to subsequently slide the channel of the window blinds into the brackets. To accommodate the extreme end positions of the lift cords of the subject window blind, the blinds of the subject invention may further comprise mounting brackets having open ended slots therein. The slots are disposed and dimensioned to receive the lift cords adjacent the extreme ends of the window blinds.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a prior art window blind.

Fig. 2 is an exploded perspective view of a window blind in accordance with the subject invention.

Fig. 3 is a cross-sectional view taken along line 3-3 in Fig. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The window blind of the subject invention is identified generally by the numeral 50 in Fig. 2. The blind 50 comprises a plurality of substantially identical slats 52 which are suspended from a channel 54 having a

tilt control rod 56 rotatably mounted therein. The channel 54 further houses a tilt control mechanism 58 in geared engagement with the tilt control rod 56. The tilt control mechanism 58 is operatively connected to a tilt wand 60 which extends downwardly from the channel 54 to a conveniently accessible location. The wand 60 may be formed from a transparent plastic material having an irregular outer surface to facilitate manual rotation of the want about its longitudinal axis. The rotation of the wand 60 causes rotation of the gears (not shown) within the tilt control mechanism 58, which in turn generates a rotation of the tilt control rod 56 about its longitudinal axis. As will be explained further herein, the rotation of the tilt control rod 56 about its longitudinal axis will affect the controlled tilting of the slats 52 of the subject window blinds 50.

With reference to Fig. 3, each slat 52 is an elongated member having opposed first and second ends 62 and 64 defining a length "c" which is selected in accordance with the width of the window to which the blinds 50 are mounted. Each slat further includes opposed longitudinal side edges 66 and 68 defining a width "d" of between about 1.25 cm. and about 5.08 cm. The slat 52 preferably is manufactured form a strip of thin metallic material which is formed from side to side to define a convex top surface 70 and a concave bottom surface (not shown) . However, it is to be understood that window blinds in accordance with the subject invention may be made with slats formed from materials other than metal and/or with slats that are substantially planar from side to side.

Each slat 52 comprises first and second lift cord apertures 72 and 74 which are formed through the slat 52 in close proximity to the respective first and second ends 62 and 64 of the slat. More particularly, the centers of the first and second lift cord apertures 72 and 74 are spaced from the respective first and second ends 62 and 64

of the slat 52 by a distence "e ⁿ which preferably is less than 5.08 centimeters, and which most preferably is approximately 0.64 cm. As with the prior art blinds, the lift cord apertures 72 and 74 depicted in Fig. 3 are of elongated configuration, with a longitudinal direction of each lift cord aperture 72 and 74 extending transverse to the longitudinal direction of the slat 52. Similarly, as with the prior lift cord apertures, the length "f" of the lift cord apertures 72 and 74 is equal to approximately one-half the width "d" of the slat 52.

Each slat 52 further includes a first pair of ladder notches 76 and 78 and a second pair of ladder notices 80 and 82. The first pair of ladder notches 76, 78 and the second pair of ladder notches 80, 82 are disposed symmet- rically along the length of the slat 52. More particu¬ larly, the first and second pairs of ladder notches 76, 78 and 80, 82 are spaced t iistance "g" from the respective first and second ends 62 and 64 of the slat 52. The distance "g" will be selected as a function of the length "c" of the slat 52 to ensure adequate gravitation support for the slat 52 as well as support against most forces that may be exerted on the slat during normal usage of the blinds. In most instances, the length "g" will equal approximately 20-25 percent of the overall length "c" of the slat 52. Additionally, in some instances, more than two pairs of ladder notches 76-82 will be provided to ensure adequate support for the slats 52 on wider windows.

Each ladder notch 76-82 extends inwardly from the adjacent side edge 66 or 68 of the slat 52 a distance "h" of approximately 0.13 cm to 0.25 cm. The actual dimen¬ sions of each notch 76-82 will be a function of the dimensions of the ladders used with the blinds 50 as explained herein.

Returning to Fig. 2, the blinds 50 of the subject invention further comprise first and second lift cords 84 and 86 which pass respectively through the first and second lift cord apertures 72 and 74 in each slat 52. The

first end of each lift cord 84 and 86 is connected to a bottom rail 88 of the window blind 50. The second end of each lift cord 84 and 86 is threaded up through a lift control mechanism 90 mounted in the channel 54 and back 5 down to a convenient elevation below the channel 54. Appropriate pulling forces exerted on the second ends of the lift cords 84 and 86 will effect the upward collapsing of the array of slats 52 of the window blind 50.

The window blind 50 further comprises first and 0 second tilt control and support ladders 92 and 94. The first tilt control and support ladder comprises first and second runners 96 and 98 respectively which are engaged in the ladder notches 76 and 78 respectively on each slat 52. The second tilt control and support ladder 94 includes 5 first and second runners 100 and 102 which are engaged respectively in the ladder notches 80 and 82 of each slat 52. The tilt control and support ladders 92 and 94 further comprise transverse slat supports 104 and 106 respectively as shown most clearly in Fig. 3. The trans- 0 verse slat supports 104 and 106 are connected to the respective runners 96, 98 and 100, 102 at equally spaced locations therealong. The runners 96-102 of the tilt control and support ladders 92, 94 extend into the channel and are mounted to the respective barrels 108 and 110 on 5 the tilt rod 56. Thus, rotation of the tilt rod 56 causes a corresponding rotation of the barrels 108 and 110 and a corresponding vertical shifting of the runners 96-102 of the tilt control and support ladders 92 and 94. This vertical shifting of the runners 96-102 changes the

30 angular alignment of the transverse slat supports 104 and 106 of the respective ladders 92 and 94, and thereby adjusts the tilt of the slats 52 substantially as in the prior art.

As shown most clearly by comparing the window blind

35 50 of the subject invention as illustrated in Fig. 2, with the prior art blind 10 in Fig. 1, it will be appreciated that there are no lift cord apertures on the subject blind

50 of Fig. 2 in the vicinity of the tilt control and support ladders 92 and 94 as had been the case in the prior art depicted in Fig. 1. Rather, the central portions of the slats 52 comprising the subject window blind 50, and in particular portion in the vicinity of the tilt control and support ladders 92 and 94 are substan¬ tially free of apertures extending therethrough. The very small ladder notches 76-82 are virtually entirely hidden by the runners 96-102 of the tilt control and support ladders 92 and 94. In contrast to the prior art, the lift cord apertures 72 and 74 of the slats 52 in the subject window blind 50 are disposed adjacent the extreme respective first and second ends 62 and 64 of each slat 52. This portion of the window blind 50 is significantly less obtrusive than the central portions for the lift cord apertures which have been employed in the prior art blinds described and illustrated above. Furthermore, these extreme end positions for the lift cord apertures 72 and 74 are generally in alignment with portions of the window frame so as to substantially prevent the passage of light through the subject lift cord apertures 72 and 74. Additionally, this end position for the lift cord apertures 72 and 74 often is completely obscured by other window treatments, such as draperies or curtains. Thus, the lift cord apertures 72 and 74 described and illustrated herein will substantially avoid the passage of light therethrough by virtue of adjacent portions of the window frame and may be entirely visually obscured by adjacent window treatment. As noted above, window blinds are mounted to an upper support portion adjacent a window by a mounting bracket. The window blind 50 of the subject invention employs a mounting bracket 112 as depicted in Fig. 2. The mounting bracket 112 includes a top support wall 114 a rear support wall 116 connected to and extending from the top support wall 114 and a bottom support wall 118. A front cover 120 is hingedly attached to the top support wall 114 and is

rotatable into engagement with the bottom support wall

118. The top support wall 114 includes a plurality of apertures 122 for receiving screws or other such supporting means therethrough. The bottom support wall 118 further includes apertures 124 which are generally in register with the apertures 122 in the top support wall 114. The apertures

124 in the bottom support wall 118 are provided to permit passage of a screwdriver or other such tool for mounting screws, or the like, through the apertures 122 in the top support wall 114. The bottom support wall 118 further includes a lift cord slot 126 extending into a front portion of the bottom support wall 118 and toward the back support wall 116. In use, the bracket 112 will be mounted to an appropriate support adjacent a window by screws or the like passing through the apertures 122 in the top support wall 114. The front cover 120 will then be hingedly rotated into the orientation shown in Fig. 2, and the channel 54 of the blind 50 will be slid in a front to rear direction relative to the mounting bracket 112. This front to rear movement will enable the lift cords 84 and 86 to slidably enter the lift cord slot 126 in each respective bracket 112 without affecting either the mounting of the blind 50 or the subsequent operation thereof.

In summary, the window blind of the subject invention provides a visually more attractive appearance and more effective control of light and other environmental conditions. The blind comprises a plurality of slats having lift cord apertures at extreme end locations thereon, and preferably having their respective centers spaced only about 0.64 cm. from the respective end of the slat. The slats of the subject window blind further include at least one ladder notch in a side edge thereof for engaging and ensuring proper positioning of the slats and the ladders relative to one another. The small ladder notches are then engaged by the ladders on the window

blind and are virtually obscured thereby. The supporting portions of the slat are substantially stronger than prior art slats having lift cord apertures at central locations thereon. The mounting brackets for the window blind of the subject invention may include lift cord receiving slots extending therein to accommodate extreme end disposition of the lift cords.

While the invention has been described with respect to a preferred embodiment, it is apparent that various changes can be made without departing from the scope of the invention as defined herein. In particular, the lift cord apertures may be moved slightly inwardly from the preferred extreme end positions depicted in the figures described and illustrated above. Additionally, more than two tilt control and support ladders may be provided, depending upon the width of the window upon which the subject blinds are employed. Furthermore, other means for positioning the tilt control and support ladders relative to the slats may be provided. For example, it may be found desirable to provide less than two notches for each tilt control and support ladder. These and other variations of the subject invention will be apparent to the person skilled in this art having read the subject disclosure.