Flexible or portable closure – partition – or panel – Plural and/or with rigid closure – Roll type
Reexamination Certificate
2001-07-25
2004-02-10
Purol, David M. (Department: 3634)
Flexible or portable closure, partition, or panel
Plural and/or with rigid closure
Roll type
C160SDIG007
Reexamination Certificate
active
06688369
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to window coverings and, more particularly, to fabric window coverings provided with adjustable vanes for controlling the amount of light passing therethrough. The present invention also includes methods and apparatus for producing such a window covering.
Fabric window coverings are often preferred by consumers for a number of their features. The features most often considered desirable are the softer appearance relative to traditional Venetian blinds, the uniform appearance which they provide a window, and the insulating properties associated with cellular fabric shades.
Cellular fabric shades offering these features are known in the art. For example, U.S. Pat. No. 4,450,027 to Colson discloses cellular window coverings which may be made of fabric or film materials. In the process disclosed in the Colson patent, a flexible strip material is folded into a continuous longitudinal tube and the longitudinal folds thus created are permanently set by passing the tubing material around a heat setting wheel.
Adhesive is applied along one side of the flattened tubular material which is subsequently stacked by winding onto a rack having flat surfaces. The winding in this manner presses the adhesive to the next layer wound onto the rack to form a bonded unitary stack of closed tubular cells. When the ends are cut from the rack the stack may be expanded and the permanently set creases provide a neat and uniform outward appearance.
U.S. Pat. No. 4,732,630 to Schnebly discloses a modification to the Colson process described above. In the Schnebly patent a hot-melt adhesive is applied to one side of the tubular material. After the flat tubular strips have been stacked and cut, they are placed in an oven under pressure and the hot-melt adhesive is activated to bond the layers together.
Both of the above patents disclose window coverings which exhibit the desirable features discussed to this point. However, window coverings of that type lack one feature which is often desired by consumers. That feature is the ability to control the amount of light admitted through the window covering, similar to a traditional venetian blind. There have been some attempts to provide a fabric window covering with the ability to control the amount of light entering the room. However, these attempts have lacked one or more of the features discussed above and have been less than successful.
U.S. Pat. No. 3,384,519 to Froget discloses one such attempt. The window covering disclosed therein consists of two cloth layers spaced apart by movable parallel blades having each of their marginal edges heat-welded to one of the movable cloth layers. With this window covering, relative movement of the two cloth layers in a direction perpendicular to the blades changes the angle of the blade and thus controls the amount of light admitted through the article. A number of undesirable features of the Froget window covering derive from the fact that it is constructed utilizing a heat-welding a process. First, this limits the fabrics which may be utilized to thermoplastic materials. Also, heat-welding necessarily requires a melting of at least some of the fibers of the materials bonded, thus providing an uneven outer appearance along the heat-welds and producing unwanted crimps or creases in the materials, which can result in fatigue failure. Further, heat-welding is a relatively slow process which may require six or more seconds to create a bond over an extended length. This is too slow for application in high volume commercial production processes. Other drawbacks of the Froget window covering are that heat welds are limited in strength, especially at elevated temperatures experienced by an insulating type shade placed adjacent a sunlit window; and the difficulty in achieving uniformly straight heat welded joints over an extended length.
U.S. Pat. No. 2,865,446 to Cole discloses a window covering in which a long rectangular piece of fabric is doubled back upon itself and a plurality of pleated elements are placed between the folded over sheets. The pleated elements are an accordion-pleated fabric which extends when the two sides of the folded over fabric are moved relative to one another in a direction perpendicular to the accordion pleats. Such a window covering does not provide a uniform appearance because the accordion-pleated fabric located closer to the top of the window covering does not expand to the same extent as the fabric closer to the bottom of the window covering. Also, it is very difficult to ensure that such accordion-pleated fabric returns to its desired position after each expansion.
The construction of Cole inherently creates an undesirable feature if a woven type sheer fabric is used for the folded over, long rectangular piece of fabric. That undesirable feature is a moire effect or interference pattern which would result when light is viewed through the folded over fabric. The Froget window covering would also appear to have this drawback because the embodiment shown in
FIG. 8
of that patent appears to show front and back fabrics of the same material.
French Patent No. 1,309,194 discloses a curtain with variable opacity. In this curtain, screen or mesh parallel sides are provided with tiltable braids therebetween. The braids are said to be attached at their edges to the sides, however, no means for attachment is specified. The drawings appear to indicate a hinged type attachment and the specification ends by stating that the difficulties of construction are substantial.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a fabric light control window covering comprising first and second parallel sheer fabric sides and a plurality of opaque or semi-opaque vanes extending between the sheer fabric sides with the vanes being angularly controllable by relative movement of the sheer fabric sides.
Another object of the invention is to provide such a window covering which has a neat and uniform construction and outer appearance in all degrees of light control. In this respect a feature of the present invention is therefore adhesive bonding of the light control vanes to the sheer fabric utilizing linear application of the adhesive and, thus, a high degree of controllability of the adhesive application process and bonding of the vane. Such a feature provides advantages other than simply an improved outward appearance. The precisely uniform construction improves the operation of the blind by preventing warps or distortions from developing over the life of the blind.
Another object of the invention is to provide such a blind which operates with a high degree of repeatability, that is, always returns to the same appearance when closed. Thus, a feature of the present invention is attachment of the vanes to the sheer fabric sides such that the vanes tend to bias the window covering toward the minimum light admitting position. A further feature of the invention in this respect is a novel heat setting of the three layers together in order to provide a uniform and wrinkle-free shade at any temperature in subsequent use. These features allow the window covering to maintain its original shape and appearance even in the presence of temperature extremes encountered in a window environment.
A further object of the present invention is to provide methods and apparatus capable of producing the above window covering. One of the features of the present invention is adhesive bonding by means of adhesive linearly applied on the vane material. Linear application ensures a high degree of accuracy and provides uniform and straight adhesive lines. Another feature of the invention is the unique heat setting process utilizing hot and cold rollers and tension belts or hot and cold flat plates and belts to uniformly press the sandwiched fabrics during reheat setting and thus guarantee a wrinkle-free structure.
It is also an object of the present invention to provide such methods and apparatus which are suitable for high volume commercial type product
Colson Wendell B.
Swiszcz Paul G.
Dorsey & Whitney LLP
Hunter Douglas Inc.
Purol David M.
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