Flexible or portable closure – partition – or panel – Pleating type – With preformed pleats
Reexamination Certificate
2002-03-20
2004-11-30
Johnson, Blair M. (Department: 3634)
Flexible or portable closure, partition, or panel
Pleating type
With preformed pleats
Reexamination Certificate
active
06823923
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the field of window coverings, and more particularly, to a light-control window covering and a method and apparatus for its manufacture.
BACKGROUND OF THE INVENTION
Light-control window coverings typically include a front and rear portion made from a sheer material and a plurality of opaque vanes extending between the sheer materials. The light-control covering is movable from an open, light-passing position in which the vanes are horizontal, to a light-blocking position in which the vanes are substantially vertical. The prior art light-control window coverings and the apparatus and method for the manufacture of the light-control coverings have a number of problems and shortcomings. One problem with these light-control products is the lack of strength of the connection between the vanes and the sheer materials. Additionally, the appearance of the connection between the vanes and the sheer materials may be uneven or may not adequately match the color or pattern of the vanes and/or sheer material. Further, the profile of the vanes of some of these light-control products does not maximize the viewable area when the light-control window covering is in the light-passing position. Additionally, the apparatus and method for manufacturing the light-control window coverings are slow and require that only a portion of the light-control product be assembled at a time.
Numerous methods have been developed to form light-control window coverings. U.S. Pat. Nos. 3,384,519 and 3,661,665 to Froget disclose a method of welding the marginal edges of a plurality of vanes to two layers of material. First, each vane is welded to one face of the first layer of material. As each vane is welded to the first layer of material, the first layer and the welded vane are wound onto a reel. After all of the vanes have been welded to the first layer of material and wound onto a reel, the combination is then unwound such that the free edge of each vane comes into contact with a second layer of material. The free edge is then welded to the second layer of material. In this manner a light-control window covering is formed with one face of the vane being welded at its marginal edge to the first layer and the second face of the vane being welded at its second marginal edge to the second layer.
U.S. Pat. No. 5,313,999 to Colson et al. describes a method and apparatus for forming a light-control window covering in which one side of individual vanes are attached with adhesive to a first continuous sheet of material and the other side of the vanes are then attached with adhesive to a second continuous sheet of material. The first and second sides of each vane are attached to the first and second sheets one at a time. Colson et al. argued that the Froget window covering had a number of undesirable features, including an “uneven outer appearance”; “producing unwanted crimps and creases in the material, which can result in fatigue failure”; that the process is a “relatively slow process”; “that heat welds are limited in strength”; and “the difficulty in achieving uniformly straight heat welded joints over an extended length.” (See col. 1 line 66-col. 2 line 17).
However, the solutions proposed by Colson et al. also have a number of drawbacks. First, the adhesive that is used to provide the bond between the vanes and the sheer materials is applied to one vane at a time, making the manufacturing process relatively slow. Additionally, the adhesive requires special additives to reduce yellowing and discoloration of the adhesive as well as subsequent processing of the bond to “roughen” the glue to provide a dull appearance. Another problem with the Colson et al. window covering is the bias of the vanes toward the light-blocking position. This bias requires additional force to move the vanes to the light-passing position and to maintain them in that position. Further, one embodiment of the light-control window covering of Colson et al. requires that the vanes do not have a crease but rather have smoothly curving portions (see col. 16 lines 25-30) and therefore do not allow for a straighter appearance of the vane. This feature reduces the viewable area when the light-control window covering is in the light-passing position. Colson et al. does disclose a second embodiment with a bend that is formed by scoring the vane material. Scoring the vane material, unlike perforating, creates a line of weakness that could result in failure of the light-control covering.
U.S. Pat. No. 5,228,936 to Goodhue, describes a method and apparatus for forming a light-control window covering, in which all of the vanes are attached with adhesive to the first and second sheets simultaneously. As in Froget and Colson, one side of each vane is attached to a first sheet and the other side of each vane is attached to a second sheet. Since the vanes are applied to the first and second sheets side by side, the vanes do not overlap when the window covering is in the light-blocking position. As a result, light is likely to pass through the spaces between adjacent vanes in the closed.
U.S. Pat. No. 5,888,639 to Green et al. discloses a method and apparatus for forming a light-control window covering formed by continuously welding three substrates of material together to form a three-substrate web having first and second light-control regions and a center vane or opaque region located there between. Portions of the three-substrate web are laterally offset from one another and are adhesively attached to form a light-control window covering. While this process increases the speed of manufacture of the light-control product, it still requires both an adhesive and welding operation. Additionally, it precludes the use of a single continuous sheet of sheer material for the light-control window covering.
U.S. Pat. Nos. 5,846,360; 5,885,409; and 5,891,208, to Gilldisclose a method and apparatus for manufacturing a multilayer filter by attaching first and second filter layers to a plurality of ribbons utilizing ultrasonic welding equipment.
It would be desirable to form a light-control window covering in which all of the vanes are simultaneously attached to the first and second sheets where the vanes of the resultant light-control window covering overlap one another in the light-blocking position. It would also be desirable to form a light-control window covering without the need for an adhesive bond resulting further in the need for adding materials to the adhesive to reduce yellowing, or processing of the bond to dull the adhesive bond. It would also be desirable to form a light-control window covering that had an increased viewable area when the light-control window covering is in the light-passing position. It would be further desirable to form a light-control window covering with a strong bond without the need for adhesive. It would also be desirable to form a light-control window covering in which at least one of the attachment areas between the vane and the sheer material is hidden by a portion of the vane, when the light-control window covering is in the light-passing position. It would also be desirable to form a light-control window covering with all of the benefits noted above.
SUMMARY OF THE INVENTION
Accordingly, an embodiment of the invention is a light-control window covering where all of the vanes are simultaneously attached to the first and second sheets. The vanes of the resultant light-control window covering overlap one another in the closed or light-blocking position.
Another feature of the light-control window covering includes ultrasonic welds between the vanes and the sheer material without the need for an adhesive bond. The ultrasonic weld does not yellow, and/or does not have a gloss appearance, and/or blends in with the sheer materials and the vanes, and/or has its own pattern.
A further feature of the light-control window is that each vane includes a crease to provide a greater viewing area when the light-control window covering is in the light-passing position.
Another feature
Palmer Roger C.
Stephenson Warren
Dorsey & Whitney LLP
Hunter Douglas Inc.
Johnson Blair M.
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