The present invention relates to a safety release mechanism for Roman Shades or Blinds. Roman Shades or Blinds are a popular choice in window coverings, and each are generally made of fabric in such a way that a unitary piece of fabric is hung vertically in a window opening to block incoming light. In operation, Roman Shades or Blinds are raised or lowered through the use of two or more lift cords that are attached on each side of the bottom of the shade or hem bar, with the lift cord running along the back of the Roman Shades or Blinds and through guide rings or openings in the fabric itself, and up to or through the head rail of the Roman Shades or Blinds.
As noted above, the cords are attached at or near the bottom of the shade or hem bar, and are guided through the rings or cord guides to the top of the Roman Shade head rail and back through a pulley system or catch system such that when the cord is pulled by a user, the attachment point on the cord guides is pulled upward, thereby allowing the shade to be raised from the bottom up. As the lift cords are urged upward through pulling on the pull cord or operating the clutch mechanism, the shade or hem bar encounters each guide or ring, the fabric overlaps such that the fabric pleasantly cascades over the last folded portion.
While the lift cord mechanism for Roman Shades or Blinds results in a highly functional and aesthetically pleasing shade, the design of Roman Shades or Blinds can result in possible safety hazards to young children through the forming of cord loops in the lift cords, and the point of connection between the bottom of the shade or hem bar presents a point where a child may be trapped between the cord and the shade. While this risk is significantly mitigated by the use of a passive restraint system, such as a quality clutch mechanism or a motorized lift system, that prevents the lift cords from being pulled back through the headrail, thereby making it extremely difficult for a child to form a loop, clutch mechanisms and/or motorization options can be an expensive option so having an inexpensive device, such as is proposed here, would be a benefit, particularly for individuals with lower incomes. As such, a functional lift cord release device that would reduce entanglement in the lift cord or in the Roman Blinds or Shades by children would be appreciated.
Additionally, the development of a device that can be easily and intuitively put back together after separation, (whether intentional or accidental) is desirable for consumers. The use of a lift ball, as opposed to a geometrically shaped catch, means that it is fairly obvious to an end user how to reattach the mechanism after the lift ball has been separated from the spring release.
Additionally, a lift cord release that would be operable to allow removal of the Roman Shades from the head rail or other hardware systems for maintenance, repair, or cleaning would be greatly appreciated. However, present releases such as those disclosed in U.S. Pat. No. 7,302,738 to Nien et al, do not allow for the simple removal of a cord release, as the release mechanisms are often larger than any rings through which the lift cord passes. Conversely, those releases that would allow the lift cord to retreat through each guide or ring allow the lift cord to be pulled entirely through the lift mechanism or clutch in the head rail, often resulting in an extended repair job that requires the disassembly of the head rail, or a nonfunctional unit. As such, a lift cord release that reduces the likelihood of child entanglement and allows disassembly of the Roman Shade or Blind without the requirement of restringing the lift mechanism would be greatly appreciated.
Turning now to
It will be appreciated that according to at least one exemplary embodiment, and as shown in
Turning now to
Additionally a spring clip (a.k.a. “Alligator Clip”) may be used. By using an inner spring controlling the release force needed to pull the lift ball 74 from the spring retainer 76 may be easier to control in manufacturing. Turning now to
Furthermore, in the manufacturing of a releasable spring clip 100 it should be appreciated that different springs 130 may be utilized, with different characteristics, such as spring wire thickness or the numbers of turns in the spring to adjust the release tension of spring clip 100 to the desired level.
It will be appreciated that placing a lift ball 74 back into releasable spring clip 100 is facilitated by squeezing the lower portion of clip arms 110, thereby facilitating an easier return of lift ball 74 to spring clip 100 after it has been released, or during the process of manufacturing the shade when the lift cords have to be adjusted in order to ensure all lift cords are tied off at the same length so that the blind raised evenly. This improved ease of removal and replacement is further useful to the end consumer who may wish to remove the shade for cleaning.
It will be appreciated that the total force required to pull lift ball 74 from spring retainer 76 should vary depending upon the total weight of hem rail 60 and shade material 50, as well as the total number of lift cords 30 utilized in the particular shade design. According to at least one embodiment, the total force required to pull lift ball 74 from spring retainer 76 is no more than about 5 lbs. more than the total weight of the hem rail 60 divided by the total number of lift cords 30; is no more than about 4 lbs. more than the total weight of the hem rail 60 divided by the total number of lift cords 30; is no more than about 3 lbs. more than the total weight of the hem rail 60 divided by the total number of lift cords 30; is no more than about 2 lbs. more than the total weight of the hem rail 60 divided by the total number of lift cords 30; or is no more than about 1.5 lbs. more than the total weight of the hem rail 60 divided by the total number of lift cords 30.
According to at least one embodiment, the total force required to pull lift ball 74 from spring retainer 76 may be calculated by the amount of force required to pull a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop. According to at least one embodiment, the total force required to pull lift ball 74 from spring retainer 76 is no more than about 5 lbs. of force exerted on a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop; is no more than about 4 lbs. of force exerted on a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop; is no more than about 3 lbs. of force exerted on a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop; is no more than about 2 lbs. of force exerted on a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop; or is no more than about 1.5 lbs. of force exerted on a single lift cord 30 at approximately 90 degrees to the shade material 50 to form a loop.
According to at least one embodiment, lift ball 74 is a substantially cylindrical or spherical ball sized to be smaller than cord guides 40 to allow lift ball 74 to pass through cord guides in the event that lift ball 74 is released from spring retainer 76. As shown in
According to at least one embodiment, lift ball 74 is sized larger than any openings within head rail 20, thereby preventing retraction of attached lift cord 30 within head rail 20. According to at least one embodiment, ball 74 is sized to have a diameter of at least 0.01″ larger than the largest opening in head rail 20.
Turning now to
In at least one other embodiment, lift ball 74 may comprise a spring-loaded stop that substantially pinches the one or more lift cords 30 within hollow channel 90, similar to those stops available under the ORB brand name and available from RollEase, Inc.
According to at least one exemplary embodiment, a chart for calculating the force to release a lift ball 74 from spring retainer 76 is provided. It will be appreciated that utilizing a release weight low enough to prevent potential strangulation or entanglement while still maintaining an operable blind may be difficult, particularly when a typical pull cord blind is utilized. A relatively low release weight plays against the desire for lift ball 74 not to accidentally separate from spring release 76 during normal operation. As such, Table 1 below establishes a calculation format easily utilized by manufacturers of roman blinds to calculate the minimum number of lift cords 30 lift to be utilized when manufacturing a blind so that the weight needed to lift the blind is no more than 1.5 pounds on average per lift cord. To utilize the calculation format shown below, a manufacturer supplies: the weight in grams per meter or ounces per square yards of the fabric (or fabrics, in the case of a lined shade) used, the weight of the “battens” or cross bars used (if any), the number of cross bars used in a given length of a shade and the weight of the hem rail 60.
As an example, Table 1A shows a size grid and the weight of a shade in each size (exclusive of the headrail or pulley mechanism) for roman shades with cross bars (or battens) in sizes up to 144″ (width)×150″ (length) using a typical fabric that weighs 9 ounces per square yard, a fiberglass hem rail 60 that weighs 1.6 oz per linear foot and battens (or cross bars) that weigh 0.6 oz per linear foot and are spaced about 9″ apart. From this weight chart, a manufacturer can deduce how many lift lines to use so that the weight per lift line is no more than 1.5 pounds, as shown in Table 1B, which can optionally be used in conjunction with Table 1A. This type of calculation can be easily done by someone who is relatively versed in the program “Excel,” and can modify the chart or calculation to ensure that each lift cord has a proper release weight while maintaining sufficient overall force to allow operation of the shade. Moreover, as Table 1 shows, lift lines do not have to be spaced more closely than 12″ apart, which is reasonable for manufacturers of roman shades.
To further ensure that lift ball 74 does not accidentally separate from the spring release during operation, manufacturers of roman shades may optionally utilize a clutch mechanism with a gear reduction as the means of lifting the shade. A clutch mechanism with a gear reduction system, such as is commercially available from RollEase of Stamford Conn. or Coulisse of the Netherlands prevents end user from “jerking” the blind up quickly, thereby reducing the chance of accidental separation of lift ball 74 from spring release 76 during normal operation.
It will further be appreciated a lift ball 74 and spring release 76 may be sold in a kit form to retrofit existing roman shades to allow them to break away. For example, lift ball 74 may be included with spring release 76, with spring release 76 including a hole in its base operable to receive a screw or other fastener such that spring release 76 is attached to hem rail 60. Additionally, cord guides 40 may be included such that cord guides 40 that are sized to allow lift ball to travel through them upon release, may be included, along with a means for attaching cord guides 40 to existing roman blind 10. As such, through the sale of these elements in a unitary package, existing roman blinds 10 may be retrofitted into a safer or more convenient product.
While specific embodiments have been disclosed herein, combinations of those embodiments, as well as certain variations thereof are included in the scope of this application.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/250,087 to David Cross, titled “Roman Blind Safety Release Mechanism”, the contents of which are incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
61250087 | Oct 2009 | US |