Patent Application
20060196612
Bottom up top down (herein after “BUTD”) window coverings are often employed in situations where it is desired to selectively cover/uncover different portions of a window (i.e.—top portions and bottom portions). The use of standard window coverings, whether typical Venetian blinds, cellular shades or the like, only allows for the covering of a window from the top of the window down. Therefore, the covering of the window using such standard window coverings always insures that either the entire window is uncovered, or at least a top portion of the window is covered. BUTD window coverings are made so that they can be raised and lowered from the top as well as from the bottom. Thus, a user can selectively cover or uncover either the top portion or bottom portion or some intermediate portion of a window.
Prior art BUTD window coverings include a headrail, an intermediate rail, and a bottom rails. A window covering material is often disposed between the intermediate rail and the bottom rail, and in certain BUTD window coverings, between the headrail and the intermediate rail. Prior art BTUD window coverings typically utilize one set of lift cords for the bottom rail, and another set of lift cords for the intermediate rail. These cords are operated independently of each other, and typically locked in place with cord locks. Thus, movement of the intermediate rail or the bottom rail requires the use of different mechanisms that each must be manipulated to engage or disengage the cord lock to hold or release the given rail. This setup typically causes confusion as to which lock operate. Similarly, where the mechanisms for engaging or disengaging the cord locks are cords or chains, the abundance of the cords or chains creates a situation in which tangling is likely.
Therefore, there exists a need for a cordless or chainless BUTD window covering.
The present invention relates to window coverings and lifting mechanisms, more particularly, to bottom up top down window coverings incorporating the use of a spring motor.
A first aspect of the present invention is a bottom up top down window covering. The window covering according to this embodiment includes a headrail, an intermediate rail, a bottom rail, at least one lift cord extending through each of the headrail, intermediate rail and bottom rail, means for balancing and tensioning the at least one lift cord, and means for retracting the at least on lift cord. The means for balancing and tensioning the at least one lift cord may be posts or unidirectional wheels among other means. The means for retracting the at least one lift cord may be a spring motor or any other suitable means as is known in the art.
Another embodiment of the present invention is another bottom up top down window covering. The window covering according to this aspect includes a headrail, an intermediate rail, a bottom rail, at least one lift cord extending through each of the headrail, intermediate rail and bottom rail, at least one post located in said intermediate rail, and at least one spring motor operatively connected to the at least one lift cord. The at least one lift cord is frictionally engaged with the at least one post, and the at least one lift cord is capable of being retracted by the at least one spring motor.
The window covering according to the above embodiment may include a pair of lift cords, a pair of posts and a single spring motor located in the bottom rail for retracting the pair of lift cords. The intermediate rail may be moveable with respect to the headrail and the bottom rail. The frictional engagement of the lift cords with the posts is achieved by wrapping each lift cord around a different post. The spring motor according to this embodiment may include a main body, a pair of cord spools rotatably mounted on the main body, each of the cord spools connected to one of the pair of cords, a drum rotatably mounted on a central portion of the main body, the drum in rotatable engagement with the pair of cord spools, and a pair of coil springs connected to the drum, the coil springs each being biased to rotate the drum which rotates the cord spools to wind the each of the cords onto one of the spools. The window covering may also include a locking mechanism to releasably secure the cords in position. Actuation of the locking mechanism allows movement of the bottom rail.
An upward force applied to the bottom rail of the window covering according to this embodiment may allow the intermediate rail to move downward. The intermediate rail may also be positioned by applying a force directly thereto. In certain configurations, the window covering may additionally include a centrally located pulley in the intermediate rail. The at least one lift cord may be wrapped around the pulley. Finally, the window covering may include shade material having two ends. One end of the shade material may be connected to the intermediate rail and the other end may be connected to the bottom rail.
Another embodiment of the present invention is another bottom up top down window covering. The window covering according to this embodiment includes a headrail, an intermediate rail, a bottom rail, at least one lift cord extending through each of the headrail, intermediate rail and bottom rail, at least one unidirectional wheel located in said intermediate rail, and at least one spring motor operatively connected to the at least one lift cord. The at least one lift cord is engaged with the at least one unidirectional wheel, and the at least one lift cord is capable of being retracted by the at least one spring motor.
Yet another embodiment of the present invention is another bottom up top down window covering. The window covering according to this embodiment includes a headrail, an intermediate rail including a pulley, a bottom rail including at least one spring motor, and a pair of lift cords. Each lift cord is wrapped around the pulley. Each lift cord has an end connected to the headrail and an end operatively connected to the at least one spring motor, where the lift cords are capable of being retracted by the spring motor.
Another aspect of the present invention is a method of positioning a bottom up top down window covering. The method according to this aspect includes providing a window shade including a head rail, an intermediate rail, a bottom rail, at least one lift cord extending through each of the headrail, intermediate rail and bottom rail, means for balancing and tensioning the at least one lift cord, and at least one spring motor operatively connected to the at least one lift cord, wherein the at least one lift cord is capable of being retracted by the spring motor. The method also includes moving the bottom rail upwardly or downwardly, wherein movement of the bottom rail downwardly includes pulling the at least one lift cord away from the spring motor, and movement of the bottom rail upwardly includes lifting the bottom rail while the at least one lift cord is retracted by the spring motor. Finally, the method also includes the step of moving the intermediate rail.
A more complete appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which:
In describing the preferred embodiments of the subject matter illustrated and to be described with respect to the drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to any specific terms used herein, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Referring to the drawings, wherein like reference numerals represent like elements, there is shown in the Figures, in accordance with embodiments of the present invention, a bottom up top down cordless window covering designated generally by reference numeral 10. As shown in
According to one preferred embodiment,
As is best shown in
In a first way, a force may be directly applied to intermediate rail 14 by a user. Such force may be sufficient to overcome the frictional force provided by the cooperation of the posts and the lift cords. It is contemplated that the force applied directly to intermediate rail 14 may be applied in such a fashion so as to allow the raising or lowering of the rail. Additionally, in a second way, intermediate rail 14 can be lowered by lifting up the bottom rail 16, and therefore removing the hanging weight force, and thus lessening the tension on the cords. This lifting of bottom rail 16 dramatically decreases the frictional force between the posts and the lift cords, and allows intermediate rail 14 to descend along lift cords 20 and 22 under its own weight. Thus, absent a force applied directly to intermediate rail 14 or the lifting of bottom rail 16, intermediate rail 14 is designed to remain in place. It is contemplated that posts 26 and 28 can be constructed in a manner or of a specific material that increases the aforementioned frictional force. For example, posts 26 and 28 can be constructed of a rubber material having a relatively high coefficient of friction.
As is also shown in
It is contemplated that different embodiments may include different combinations of the elements previously disclosed. For example, while the embodiment shown in
The lifting mechanism depicted in various views in
Spring motor assembly 112 further comprises a drum 134 rotatably mounted on a central portion of main body 124. Drum 134, like spools 126 and 128, may include a bore 135, as best seen in
According to one or more embodiments, drum 134 is in rotatable engagement with the pair of cord spools 126 and 128. Drum 134 is preferably in rotatable engagement with cord spools 126 and 128 via engagement surfaces such as gears associated with each of the spools and the drum. For example, spool 126 may include a gear 136, and spool 128 may include a gear 138, both of which engage with a gear 144 associated with drum 134. As shown in
Mounting of drum gear 144 on drum 134 may be accomplished by providing complementary mating surfaces on the drum and the gear. For example, drum 134, may include a male hexagonal surface 140, as seen in
According to one or more embodiments, spring motor assembly 112 further includes a pair of coil springs 146 and 148 disposed loosely around spindles 130 and 132, but without storage spools. Preferably, each coil spring 146 and 148 is located coaxially with each of cord spool 126 and 128. Thus, in certain embodiments, cord spools 126 and 128 are respectively disposed above the coil springs 146 and 148. Coil springs 146 and 148 are connected, on one end, to drum 134. When bottom rail 16 is in a raised position, a major portion of the coil spring is wrapped around its respective spindle. When the bottom rail 16 is pulled down a portion of each spring is transferred onto drum 134. Springs 146 and 148 are attached to center drum 134 and configured in a way that when center drum 134 is rotated while bottom rail 16 is being lowered, both of springs 146 and 148 resist (or act opposite) such rotation. When window covering 10 is raised again by lifting bottom rail 16 and releasing a locking device (described below), coil springs 146 and 148 are biased to rotate drum 134, and the drum rotates cord spools 126 and 128 to wind cords 20 and 22, onto their respective spools. Thus, coil springs 146 and 148, do not directly drive cord spools 126 and 128, and they are not in contact with the cord spools. In other words, while the window covering is being raised, coil springs 146 and 148 are biased to rotate a member separate from the cord spools, and this member in turn rotates the cord spools. The coil springs are selected and biased with sufficient force so that cord spools 126 and 128 are driven with sufficient force by drum 134 to take up their respective cords 20 and 22 while the blind is being raised.
Preferably, coil springs 146 and 148 are releasably attached to drum 134. Drum 34 further includes spring engagement surfaces 150 and 152 (not shown), which are in the form of arcuate slots formed in drum 134. Preferably the drum is hollow, and each spring 146 and 148 has a partially narrowed end section 156 and 158. Springs 146 and 148 preferably have the same thickness and the width “w” of the spring is substantially the same over the length of the spring. In preferred embodiments, both ends of each spring 146 and 148 have the same width. Partially narrowed end sections 156 and 158 provide an engagement surface with spring engagement surfaces 150 and 152 of the drum. Thus, each spring 146 and 148 is engaged with drum 134 by inserting narrowed end sections 156 and 158 in one of the arcuate slots in drum 134 and then turning each end section 156 and 158 approximately 90 degrees to lock spring 146 and 148 to the drum. Of course, other means can be used to engage springs 146 and 148 and drum 134. For example, tabs, complementary spindles and openings and other means can be utilized to engage achieve the same result.
According to one or more embodiments, spring motor assembly 112 further includes a release device or locking mechanism 154 to releasably lock the cords in place and prevent the cords from winding onto the spools when bottom rail 16 is in a lowered position on a window. Preferably locking mechanism 154 is associated with main body 124. Main body 124 includes a pair of cord slots 160 and 162 (shown in
As best shown in
In use, the cords 20, 22, are taken up on spools 126 and 128 when the cords are released from the pinched configuration by squeezing locking handle 174 and lifting up on bottom rail 16. Coil springs 146 and 148 rotate drum 134 and cause cord spools 126 and 128 to take up the cords as the bottom rail is being lifted. In one or more embodiments, the drum provides substantially uniform rotation for each spool 126 and 128, resulting in even lift of the window covering. Thus, when hand-operated locking mechanism 154 is released and it is desired to move bottom rail 16 upward, the tendency of springs 146 and 148 to return to their natural state causes center drum 124 to rotate in a direction that causes springs 146 and 148 to return to positions loosely surrounding posts 130 and 132. This causes center gear 144 to rotate, which in turn causes cord gears 136 and 138 to rotate, thus taking in lift cord.
Referring to
Thus, according to one or more embodiments of the present invention, a lifting mechanism is provided in which two springs are taken up by a central drum, which acts as a single output drum, providing a compact, powerful unit that provides even lift of the window covering. The two separate springs are positioned directly below the cord spools but not directly connected to the cord spools, which maximizes the use of space of the bottom rail. Thus, the lifting mechanism can replace a portion of the bottom rail and be an integral part of the rail. The locking mechanism can be concealed from view by positioning the locking mechanism to face the rear of the bottom rail. The lifting mechanism is compact in design, in part due to the fact that the locking mechanism includes two relatively thin arms that are inserted into the main body of the lifting mechanism, with cord channels or openings being located in those arms. Once again, it is contemplated that the aforementioned spring motor assembly 112 is only one example of a lifting mechanism 24 for use with bottom up top down window covering 10.
Intermediate rail 14 is situated such that the movement of bottom rail 16 in an upwards direction will, at a certain point, similarly move intermediate rail 14 in an upwards direction. Therefore, the operation of lifting mechanism 24 and the lifting of bottom rail 16 will allow for the winding of lift cords 20 and 22 and the upward movement of intermediate rail 14 upon contact of bottom rail 16. This operation of bottom rail 16 allows for the selective covering and uncovering of a window as in other window coverings that are known in the art. As discussed above, positioning of the remainder of window covering 10 may be accomplished by positioning intermediate rail 14. To move intermediate rail in a downward fashion, either a direct force may be applied by a user, or a slight lifting of the bottom rail may be done to remove the aforementioned frictional force. To move intermediate rail 14 in an upward fashion, either a direct upward force may be applied by a user, or lifting mechanism 24 may be actuated in conjunction with the lifting of bottom rail 16 until contact is made between the two rails.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
