The present invention relates generally to window coverings which have a bottom rail, such as Venetian blinds, pleated blinds, cellular blinds, and some Roman shades.
Venetian blinds, pleated blinds, cellular blinds, and some Roman shades have a headrail, a bottom rail, window covering material extending between the headrail and the bottom rail and lift cords extending from the headrail to the bottom rail. The bottom rail may be rectangular and have a height as small as one half inch and as large as two inches. Some bottom rails have a curved front face or a curved bottom. Other bottom rails are cylindrical. Typically, one end of each lift cord is attached to and wound on a spool in the headrail and the opposite end of the lift cord is attached to the bottom rail. The spools on which the lift cords are wound may be on a common shaft that is operated by a pull cord or a cord loop. In cordless blinds there are spring motors which provide the force for winding the spools that contain the lift cords. U.S. Pat. No. 5,482,100 to Kuhar discloses a cordless, balanced Venetian blind or shade with consistent variable force spring motor. This system uses spring motors to balance the weight of the bottom rail and the accumulating window covering material as the window covering is raised or lowered by simply grasping the bottom rail and urging it upwardly or downwardly.
A problem common among window coverings having a bottom rail is balancing of the bottom rail so that it is level when the window covering material is at a fully lowered or partially lowered position. In many window coverings the lift cord extends through a hole in the bottom rail and is held in place by a knot tied in the lift cord. When the window covering is installed the installer can level the bottom rail by changing the location of the knot on selected lift cords. In other window coverings a clamp in provided in the bottom rail for attaching the lift cord to the bottom rail. In this product the installer can lengthen or shorten the lift cord by unclamping, moving and re-clamping the lift cord.
Many window coverings have weights in the bottom rail that can be moved left or right on the bottom rail. Because the lift cords are usually polyester adding weight to or shifting weight on the bottom rail will stretch the lift cord and thus can be used to level the bottom rail. One easy method to level a bottom rail is to use weighted, tape-like strips which are adhered to the bottom rail by the fabricator at appropriate locations. Most frequently, such strips are applied after the window covering has been fabricated and after it has been determined where any imbalance may exist. Another approach for resolving the weight balance issue is disclosed by Colson et al. in U.S. Pat. No. 5,320,154. They teach a weight element that is slidably disposed in the bottom rail and is moved longitudinally along the bottom rail until appropriate balance is achieved. U.S. Pat. No. 6,769,471 to Voss et al. discloses another approach to using weights to level a bottom rail.
While all of these approaches provide methods for achieving a level bottom rail, they suffer from one or more drawbacks with regard to installation and/or use. First, none of these systems are easy for a consumer to use and some require the use of specialized tools. Second the balance of the bottom rail may change after the window covering has been hung because the window covering material or the a cord may have stretched or contracted unevenly along its length causing one end of the bottom rail to be lower than the other end. Should that occur it may be necessary to dismantle the bottom rail and readjust the cord length or the weight and balancing system. Even if the weights on the bottom rail are easily accessible, repositioning those weights to level the bottom rail may be difficult, depending on the skill of the owner or user of the window covering.
Consequently there is a need for a bottom rail which is easy to level, not only at the time of installation but also after the blind has been hung in place for several months or even years.
There is also a need for a bottom rail level adjusting device which can be used on the bottom rails which are currently in use. Indeed, such a bottom rail level adjustor should be capable of being retro-fitted on existing blinds.
I provide a bottom rail leveling device that has a housing having a base, a top and a sidewall extending between the base and the top. The top has an opening through which a lift cord passes. The base has a first opening through which a lift cord passes and a second opening. A spindle is positioned within the housing, such that the bottom end of the spindle is positioned over the second opening in the bottom of the housing. That bottom end is configured to receive a tool for turning the spindle. The spindle has a peripheral edge with spaced apart notches that are engaged by a projection extending from the housing. Turning the spindle causes the lift cord to be wound around or unwound from the spindle which shortens or lengthens that lift cord to level the bottom rail.
I prefer to provide a cord anchor clip within the housing and adjacent the first opening in the base which is attached to the lift cord.
I prefer to make the housing as two halves connected together by at least one strap. The first half and the second half each containing a portion of the sidewall, the top and the bottom of the housing. I further prefer to provide a socket on one half that receives a pin that extends from the other half to align the halves and hold them together. This housing can be made of plastic with the two halves and strap or straps being molded as a single piece.
Other objects and advantages of my bottom rail level adjusting device will become apparent from certain present preferred embodiments thereof which are shown in the drawings.
Referring to a description of
The shape for the bottom rail can be selected from those known to the art and is typically made of from steel or aluminum and are painted an appropriate color for the window covering. Vinyl materials may also be employed and are in common use for lower-priced point applications. In the window blind 10 shown in
Referring to
Although I prefer to provide the notches on the peripheral edge of the bottom end 31 of the spindle 30 they could be located on the peripheral edge of the top end 32 of the spindle. Yet another option is to arrange the notches on the top surface of the top end 32 of the spindle and provide the projection that engages those notches on the inside surface of the top 24 of the housing 21. Another alternative is to arrange the notches on the outer surface of the bottom end 31 of the spindle 30 and provide the projection that engages those notches on the inside surface of the base 18 of the housing.
I prefer to make the housing 21 in two halves 1 and 2 connected together by two straps 3. As a result the housing can be molded from plastic as one piece. The first half 1 of the housing contains a pair of sockets 5 that each receive an alignment pin 4 on the second half 2 of the housing 21. The alignment pins are sized and positioned to fit within the sockets such that the two halves 1 and 2 can be snap fit together. Both the housing and the spindle can be made from a plastic such as polyvinyl chloride or polycarbonate.
I also prefer to provide a tab or catch tooth 41 and 42 on the exterior of each half 1, 2 of the housing 21. The catch teeth enable the halves to be snap fit into a bottom rail 14 as shown in
To install the bottom rail level adjustor 20 on the bottom rail of a window covering the installer routes the lift cord from the headrail, through the window covering material and through a hole in the cover 9 on the bottom rail 14. See
The bottom rail level adjusting device which has been disclosed can be installed in all or nearly all types of bottom rails in use today. This bottom rail level adjustor can also be retro-fitted on the bottom rail of existing blinds.
Although I have shown and described certain present preferred embodiments of my bottom rail leveling device and window coverings containing this device, my invention is not limited thereto but may be variously embodied within the scope of the following claims.
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Number | Date | Country |
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102009008774 | Aug 2010 | DE |
Number | Date | Country | |
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20150240558 A1 | Aug 2015 | US |