# Patent

## Title
Skew adjustment device for coverings for architectural openings

## Abstract

A device for correcting skew in roll-up retractable coverings for architectural openings includes a friction device positioned within the head rail for movement between releasably fixed positions and disposed for engagement with the fabric of the covering to regulate the rate at which the fabric is wrapped about a roller in the covering at selected locations along the length of the roller to correct for any inherent skew in the covering.

## Background
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit under 35 U.S.C. § 119(e) to U.S. provisional patent application No. 60/747,957 (“the '957 application”), which was filed on May 23, 2006 and entitled “Skew Adjustment Device For Coverings For Architectural Openings.” The '957 application is incorporated by reference into the present application in its entirety.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to coverings for architectural openings and more particularly to a skew adjustment device positioned within the head rail of the covering to maintain a uniform rollup of covering fabric onto a roller disposed within the head rail.
2. Description of the Relevant Art
Coverings for architectural openings have assumed different forms over many years. Early forms of coverings simply consisted of fabric draped across all or some portion of an architectural opening such as a door, archway, window or the like.
Retractable coverings have also been a popular product wherein the covering is either suspended vertically and retracted to one or both sides of the architectural opening or rolled up or down about a roller at the top or bottom of the opening. The latter category of retractable coverings include a flexible fabric or fabric like material that is connected to a roller and can be retracted about the roller in a retracted condition of the covering or extended from the roller across the architectural opening in an extended condition.
One problem with retractable coverings that include a flexible material that is wound onto or unwound from a roller resides in the material skewing as it is wound onto the roller or unwound from the roller. When the material skews, it translates horizontally along the longitudinal axis of the roller as it is raised and wraps around the roller in a spiral fashion sometimes referred to as barber poling. As a result, the bottom rail along the bottom edge of the material is not desirably horizontally disposed during operation of the covering. Skewing of the material can be caused by various features of the covering including the roller not being horizontally mounted, the fabric not being fixed to the roller horizontally, or the fabric being asymmetrically configured, but regardless of the cause of the skew, it is aesthetically undesirable and can cause the fabric to engage the housing for the roller where it can fray. Accordingly, attempts have been made to correct skew.
Typically, the skew is corrected with a ballast bar or bars slidably positioned in the bottom rail of the covering so that the ballast bar or bars can be releasably fixed at any desired location along the horizontal length of the bottom rail. This of course shifts the center of gravity of the bottom rail which counters the bias in the covering material so that the bottom rail remains horizontal as desired for operation and aesthetics.
While ballast bars in the bottom rail are typically concealed within the bottom of the bottom rail, under certain circumstances, they can become visible and accordingly alternative anti-skew systems are continually being investigated.
It is to provide an alternative skew adjustment system that the present invention has been developed.
SUMMARY OF THE INVENTION
The skew adjustment system of the present invention is incorporated into the head rail of a rollup covering for architectural openings wherein the covering includes a flexible fabric or fabric-like material adapted to be wound about a roller in the head rail when retracting the covering or unwound from the roller when extending the covering. It has been found that by creating a point of increased tension on the flexible material at a predetermined fixed position along the horizontal length of the roller the tendency of the fabric to skew as it is being rolled on or unrolled from the roller can be offset.
In accordance with the present invention, an engagement arm is slidably positionable at releasably fixed positions along the horizontal length of the head rail, with the arm being resilient and adapted to slidably engage the fabric material when it is at least partially wound about the roller. The engagement arm creates a frictional drag on the material which inhibits the wrapping of the material at the location of the engagement arm while allowing other locations along the length of the roller to accept the fabric with a looser wrap so as to counter the skew bias. Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, taken in conjunction with the drawings and from the appended claims.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a retractable covering for an architectural opening shown in an extended position with a portion of the head rail removed to show the skew adjustment device of the present invention.
FIG. 2 is a front elevation of the covering of FIG. 1 with the skew adjustment device shown in dash lines.
FIG. 3 is a front elevation similar to FIG. 2 showing the covering partially retracted and with the bottom rail inclined relative to horizontal illustrating a skew in the fabric of the covering.
FIG. 4 is a front elevation similar to FIG. 3 with the covering fully retracted and with the bottom rail still forming an incline with horizontal.
FIG. 5 is a front elevation similar to FIG. 2 with the covering in a fully extended position but with the skew adjustment device having been shifted to the right.
FIG. 5A is an enlarged fragmentary section taken along line 5A-5A of FIG. 5.
FIG. 6 is a front elevation similar to FIG. 5 showing the covering in a partially retracted position.
FIG. 7 is a front elevation similar to FIG. 6 with the covering fully retracted.
FIG. 8 is an enlarged vertical section taken along line 8-8 of FIG. 7.
FIG. 9 is an isometric showing the skew adjustment device of the present invention.
FIG. 10 is a view of the skew adjustment device taken along line 10-10 of FIG. 9.
FIG. 11 is a left-side elevation of the skew adjustment device of FIG. 9.
FIG. 12 is a front elevation of the skew adjustment device.
FIG. 13 is a section taken along line 13-13 of FIG. 12.
FIG. 14 is an enlarged vertical section taken through a portion of the head rail of the covering of FIG. 1 with the skew adjustment device positioned in the head rail.
FIG. 15 is a fragmentary isometric showing the skew adjustment device being inserted into the head rail.
FIG. 16 is an isometric of a second embodiment of the skew adjustment device.



DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a covering 20 for an architectural opening such as a door, window, archway or the like is illustrated in a fully extended position. The covering can be seen to include a head rail 22 that rotatably supports a roller 24 (FIG. 5A) that is reversibly driven by a control cord 26 in a conventional manner. The roller supports a flexible fabric material 28 which for illustrative purposes is shown as being comprised of a pair of face sheets 30 of material such as sheer interconnected at vertically spaced locations by horizontally disposed translucent flexible vanes 32. Other fabric or fabric-like materials could be used in lieu of the material illustrated as will be appreciated with the description that follows. The bottom edge of the fabric material supports a rigid bottom rail 34. A fabric covering of the type illustrated is described in detail in applicant's U.S. Pat. No. 5,313,999, the disclosure of which is hereby incorporated by reference. As can also be seen in FIG. 1, at the location where the head rail is broken away, a skew adjustment device 36 in accordance with the present invention is incorporated into the head rail and the device and its operation will be described hereafter.
The covering 20 shown in FIG. 1 is shown in a front elevation in FIG. 2. As will be appreciated, the bottom rail 34 is disposed horizontally and in a parallel relationship with the head rail 22 as is desired for aesthetics. In FIG. 3, however, the covering is shown partially retracted and it can be seen the bottom rail forms an acute angle with horizontal with this position of the covering being referred to in the industry as skewed. In other words, as the fabric material is being wrapped around the roller 24, the right edge is wrapping more rapidly or more tightly than the left edge causing the bottom rail to skew or tilt as illustrated. Of course, such a skew is undesirable from an aesthetic standpoint, and in fact, when the covering is fully retracted as shown in FIG. 4, the bottom rail is clearly no longer parallel with the head rail as it was when the covering was fully extended in FIG. 2. It should also be noted in FIGS. 2-4 that the skew adjustment device 36 which is shown in dashed lines, as it is hidden within the head rail, is longitudinally centered within the horizontal head rail.
As will be more clearly appreciated with the description that follows, the skew adjustment device 36 is slidably disposed within the head rail 22 and can be releasably fixed at any position along the horizontal length of the head rail. The skew adjustment device is a frictional device that slidably engages and compresses the fabric material 28 as it is being wrapped onto the roller or unwrapped from the roller 24. The frictional engagement with the fabric material provides drag and compression at a preselected position along the horizontal length of the roller so that the rate at which the fabric wraps about the roller at the location of engagement and the tightness of the wrap can be controlled thereby controlling skew.
With reference to FIGS. 5-7, FIG. 5 shows the covering 20 fully extended and of course the bottom rail 34 is horizontal and parallel with the head rail 22. The skew adjustment device 36 is positioned to the right of center so as to correct the skew illustrated in FIGS. 2-4. In FIG. 6, the covering has been partially retracted and due to the affect of the skew adjustment device on the fabric material 28 being wrapped about the roller, the bottom rail remains horizontal and parallel with the head rail as desired. FIG. 7 shows the covering fully retracted and as will be appreciated, the bottom rail is flush and parallel with the head rail as desired.
With reference to FIGS. 9-13, the skew adjustment device 36 can be seen to be a punched or molded member that is made of a semi-rigid but resilient material such as plastic, aluminum, spring steel or the like and includes an arched plate-like back 38 with an integral forwardly and upwardly inclined engagement arm 40. The bottom edge 42 of the engagement arm is integral with the bottom edge of an opening 44 through the plate-like back of the device and due to the integral connection of the engagement arm with the back along an edge of the engagement arm and the resilient semi-rigid characteristics of the material from which the device is made, the engagement arm is spring biased so that if deflected up or down, it will be encouraged or biased to return to the neutral position shown in FIG. 9. A second opening 46 is provided through the back plate 38 adjacent to the bottom edge thereof thereby defining a somewhat flexible arched segment 47. As is possibly best appreciated by reference to FIGS. 11 and 13, the plate-like back of the device is generally arcuate and concave in a forward direction having an optional horizontally wavy or serpentine segment 48 immediately above the location of attachment of the engagement arm 40 with the back 38. An illustration of the skew adjustment device without the serpentine segment 48 is shown in FIG. 16. A flat horizontal tab 50 is provided in the device above the serpentine segment for a purpose to be described hereafter.
It should also be noted that the free or distal edge 52 of the engagement arm is hook shaped so as to provide a smooth curved forwardly convex edge portion which as will become more clear hereafter, slidably engages the fabric material 28 in the covering to correct any skew that may be inherent therein.
The head rail 22 for the covering as possibly best seen in FIG. 8, includes an arcuate front wall 54 connected to a rear component 56 and a top wall 58. The space between the front wall and an open rear of the head rail along the bottom of the head rail is also open so the fabric for the covering can be rolled onto or unrolled from the roller 24 through the open bottom of the head rail. End caps 62 are also provided at opposite ends of the head rail for aesthetics.
The front wall 54 of the head rail 22, again as probably best seen in FIG. 8, has an arcuate main body 64 continuous upwardly with an inclined flat segment 66 that is in turn continuous with a generally flat upper ledge 68 that interconnects with the top wall 58 of the rear component 56 of the head rail in a conventional manner. Adjacent to the uppermost edge of the inclined flat segment 66 of the front wall, a generally inverted T-shaped rib 70 extends inwardly perpendicularly to the inclined flat segment and defines a downwardly opening pocket or groove 72 for receipt of the horizontal tab 50 along the upper edge of the skew adjustment device 36 as will be more clear hereafter. Adjacent to the lower edge of the arcuate main body 64 of the front wall of the head rail is another generally T-shaped inward projection 74 which defines an upperwardly opening seat or groove 76 for the lower edge of the skew adjustment device.
The front wall 54 of the head rail 22 is preferably an extruded member that can be made from aluminum, plastic or other suitable material so that the features described above are formed continuously along the horizontal length of the front wall. Accordingly, the pocket 72 and the seat 76 are confronting along the inner surface of the front wall for slidable receipt of the top and bottom edges of the skew adjustment device.
With reference to FIG. 15, the skew adjustment device 36 can be seen being inserted into the space on the front wall 54 between the pocket 72 and the seat 76 by positioning the flat horizontal tab 50 along the top edge of the skew adjustment device into the pocket at the top of the front wall of the head rail and then sliding the skew adjustment device along the inner surface of the front wall of the head rail until the bottom edge of the skew adjustment device is received in the upwardly opening seat 76. The skew adjustment device, as mentioned, is made of a semi-rigid but resilient material and is sized so that it is compressed into the space between the upperwardly opening seat and the downwardly opening pocket with some spring bias being provided by the serpentine segment 48 of the skew adjustment device along with the inherent resilient characteristics of the material from which the skew adjustment device is made. Due to the flexibility of the device, it can also be inserted into the head rail laterally and snapped into place at a desired location.
When the skew adjustment device 36 is fully and slidably mounted on the front wall 54 of the head rail 22, it is positioned as seen best in FIG. 14 so as to apply pressure along the top and bottom edges against the pocket 72 and the seat 76 so that it can be releasably frictionally fixed at any position along the length of the head rail. As will be appreciated in FIGS. 5A and 8, when the skew adjustment device is desirably and slidably mounted on the head rail, the engagement arm 40 projects inwardly toward the roller 24.
The hook shaped distal edge 52 of the engagement arm 40 as mentioned above provides a smooth curved convex surface for engagement with the material or fabric 28 of the covering and due to the arcuate nature of the distal edge of the engagement arm, the arm engages the material of the covering tangentially so as not to snag the material. As will be appreciated in FIGS. 5A and 8, when the material is substantially unwrapped from the roller 24, the engagement arm remains in frictional engagement with the material as it obviously does when the material is fully wrapped about the roller as shown in FIG. 8.
The engagement of the arm 40 with the material 28 is designed to establish a frictional drag on the material and compresses the material on the roller as it is being wrapped or unwrapped from the roller. As will be appreciated by providing frictional drag and compression at a predetermined location along the length of the roller 24 the fabric is encouraged to wrap or unwrap in an unnatural way. This of course is designed to counter or offset the natural bias that may be in the fabric causing it to skew if not corrected. In other word, at the location on the fabric where the skew adjustment device 36 is engaged, the fabric is compressed toward the roller causing the material beneath the engagement arm to wrap more slowly and more tightly about the roller or unwrap more slowly and more tightly from the roller. Due to the fact that the skew adjustment device can be releasably fixed through friction at any position along the length of the head rail 22, any degree of skew or inherent bias in the covering can be corrected.
By way of example, if the skew in the covering is as illustrated in FIG. 3 with the right edge of the fabric 28 being wrapped more rapidly and more loosely than the left edge, the skew adjustment device 36 can be shifted to the right as shown in FIGS. 5-7 to provide a frictional drag and increased tension toward the right side of the fabric allowing the left side to catch up so that the covering can be extended and retracted without skew.
An alternative embodiment of the skew adjustment device is shown in FIG. 16 where again the device is made of a semi-rigid but resilient material wherein an arched plate-like back 78 of the device is smooth and does not include the serpentine segment 48 of the first-described embodiment. The device again includes an integral forwardly and upwardly inclined engagement arm 40 with the bottom edge 42 of the engagement arm being integral with the bottom edge of an opening 44 through the plate-like back 78 of the device and due to the integral connection of the engagement arm with the back along an edge of the engagement arm and the resilient semi-rigid characteristics of the material from which the device is made, the engagement arm is spring biased so if deflected up or down, it will be encouraged or biased to return to the neutral position shown in FIG. 16. Again, an opening 46 is provided through the back plate adjacent to the bottom edge thereof which defines a somewhat flexible arched segment 47 as in the first-described embodiment. The resiliency of the material and the relatively thin arched segment 47 in comparison to the remainder of the back plate enables the device to be laterally inserted and snapped into place within the head rail. It will be appreciated the serpentine segment 48 of the first-described embodiment is an optional feature of the device and is not mandatory.
Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.

## Claims

1. A rollup covering for architectural openings comprising in combination:
an elongated head rail having opposed longitudinally extending grooves, a roller and a control system for effecting reversible rotation of said roller,
a flexible material having an upper edge secured to said roller and a lower edge secured to a bottom rail, said material being wound about said roller in a retracted position of the covering and unwound from said roller in an extended position of the covering, and
a skew adjustment device slidably mounted within said head rail that releasably adjusts its position along the longitudinal length of the head rail and compressibly engages said material when said material is at least partially wound about said roller with sufficient compressive force to maintain a horizontal orientation of said bottom rail, said device including a generally planar body with top and bottom edges slidably received in said grooves and compressible between said edges and a resilient arm operatively connected to said body and positioned to compress said flexible material at a predetermined location.

2. The covering of claim 1 wherein said generally planar body is one piece.

3. The covering of claim 2 wherein the engagement of said arm with said material is substantially tangential.

4. The covering of claim 1 wherein said arm is spring biased.

5. The covering of claim 1 wherein said edges are spring biased into said grooves.

6. The covering of claim 1 wherein said body is made of a semi-rigid but resilient material and includes said arm as an integrally formed lateral extension from said body.

7. A method of maintaining a horizontal orientation of the bottom rail of a covering for an architectural opening using the device of claim 1, said covering including said head rail, said roller in said head rail, said flexible material connected along said upper edge to said roller and along said lower edge to said bottom rail, and said control system for reversibly rotating said roller to wrap and unwrap said shade material about said roller, comprising the step of compressing said shade material at the preselected location along the length of said roller to effect a substantially uniform tightness in the wrap of said material along the length of said roller.

8. The method of claim 7 wherein the compressing of the shade material is obtained with the resilient arm mounted within said head rail.

9. The method of claim 8 wherein said resilient arm is slidably movable along the length of said head rail between releasably fixed positions.

10. The method of claim 9 wherein said arm is attached to the generally planar body having top and bottom edges, and wherein said head rail includes said opposed grooves receiving said top and bottom edges of said generally planar body.