The invention relates to the field of window treatments. More specifically, the invention is a system for controlling the lift or lift and tilt of an unbalanced window treatment in the presence of a continuous retraction force.
In the construction of horizontal blinds two kinds of controls are usually desired. The blind can have a control to lift the slats of the blind. In addition, the blind may permit control over the tilt of the slats. Cords or tape will generally be attached to or through the slats of the blind and into the head rail of the blind to connect with the control apparatus. To allow a user to operate the blind, an external interface is provided. Traditionally, the interface for lifting includes a cord extending from the head rail of the blind. When separate controls are provided for lift and tilt, typically a wand is utilized to change the tilt of the slats. Depending on the control devices used in the head rail, a cord or bead chain may also be configured to provide the user interface for control over the tilt of the blind without a wand. However, these cord-type interfaces typically hang freely in a loop or as two separated lengths of cord. Recently, consumer advocates have questioned whether cord-type interfaces might potentially pose a safety hazard to children if misused.
An objective of the invention is to provide a blind that can be operated without a cord or chain user interface.
It is another objective to provide a blind that automatically and securely locks lift cords or slender lengths of flexible lifting material in place to reduce the likelihood of these materials from being pulled from the slats and becoming a possible safety hazard.
It is a further objective to provide such a blind with controls that allow a user to lift and lower the slats of the blind with ease.
It is a further objective to allow the user to have control over the tilt of the slats of the blind.
It is another object to provide such a blind with only a single control device.
A still further objective is to provide such a device that is economical and simple to manufacture.
Additional objectives will be apparent to those skilled in the art upon reading the disclosure of the invention that follows.
Generally, the invention involves an apparatus for the control of a window treatment with a cover that is raised and lowered vertically. The apparatus includes a shaft, a slender length of flexible lifting material and a gathering means coupled to the shaft to receive and wind the lifting material. The window cover is combined with the lifting material to permit the window cover to lift with the movement of the lifting material toward the shaft with the assistance of a spring means that provides a continuous retraction force for lifting the cover and coiling the lifting material by the gathering means. A brake means coupled to the shaft is provided to prevent or release the rotation of the shaft.
In one embodiment the invention is a horizontal blind with controls for the lift and tilt of slats. The blind is provided with a spring means to provide a continuous lifting or retraction force to assist the lift of the blind. The spring means also serve to assist in coiling the lifting material attached to the slats of the blind on a gathering means coupled to a shaft in the head rail. The spring means may be a blade spring or torsion spring. A brake means coupled to the shaft is provided to selectably permit or prevent rotation of the shaft. An optional rotation reducing means or gear box reduces the rotation ratio between the shaft and the spring. Optionally, one end of the spring means may traverse a track in the head rail of the blind to permit expansion and compression of the torsion spring. The spring means preferably includes a drum and a tab so that the spring may easily be loaded with a retraction force during assembly.
In one embodiment, the brake means includes a release arm, a brake spring, and a brake drum. The brake drum is coupled to rotate with the shaft and the release arm is positioned to contact the brake drum to impede rotation of the brake drum. The brake spring and release arm can be configured to maintain the release arm in frictional contact with the brake drum under force of the brake spring. A brake sleeve around the brake drum with a high coefficient of friction impedes rotation of the brake drum when the brake sleeve is interposed on the brake drum and in contact with the release arm.
In one embodiment of the blind where a tilter is provided, the brake means is combined with a tilting control means to operate the tilter to tilt the slats. The control serves as a single user interface with a release position, a brake position and a tilt position for control of movement of the slats. The brake means disengages by a lateral movement of the user interface and the tilting control means adjusts by turning or twisting the user interface. The user interface may be provided as a single wand. The user interface also optionally includes a tactile feedback means, such as a ball bearing and a spring located near grooves of the interface, to assist the user in distinguishing the release position, brake position and tilt position.
A preferred combined control includes a rod and a brake coupling with a fixed coupling portion and rotatable coupling portion. The rotatable coupling portion is mounted to the rod and the fixed coupling portion is mounted with the head rail. A helical gear key mounted on the rod fits within an aperture of a helical gear coupled to the rod and a gear coupled to the main rotational shaft of the blind.
The control permits a novel way for adjusting a window blind to the preference of a user. The rod may be moved in a lateral direction along an imaginary axis running the length of the rod to move slats in a vertical direction. Twisting the rod in a circular direction will tilt the slats. The lateral movement disengages a brake on the shaft in the horizontal window blind and the stored spring force raises the slats. Releasing the rod coupled to the shaft will stop vertical movement of the slats.
A novel method for the assembly of the unbalanced horizontal blind is also disclosed. Generally, the preferred assembly method includes providing the components of a horizontal blind, including a spring means with a drum and tab for winding the spring means. A winding strap of a pre-determined length is also provided. The winding strip being attached to the tab is wrapped around the drum before installation. The components of the horizontal blind with the spring are installed in the head rail but leaving the spring free to rotate. The shaft is rotated to gather the slats to the head rail. Afterward, the spring is partially braked and the winding strap removed, thereby turning the spring, to load a force into the spring. The installation of the spring is then completed by coupling its mount in the head rail to maintain the force loaded into the spring means. The strap may be a pre-determined length calculated to wind the spring an appropriate number of turns to load a force in the spring that will be sufficient or equivalent to the force required to lift the plurality of slats.
As illustrated in
As illustrated in
In this embodiment, the rotation end 18 is preferably engaged or coupled to a rotation reducing means 14. This rotation reducing means 14 is coupled to the head rail. The rotation reducing means 14 changes the turn ratio between the shaft 2 and the torsion spring 12. A single complete rotation of the shaft 2 will result in less than one complete rotation of the rotation end 16 of the torsion spring 12. The rotation reducing means is shown in
This reduced force is also beneficial when considering that a smaller force is required to lift or retract the slats when the slats are in the extended position EP when compared to the force required to lift the slats when they are retracted near the collected position CP. This difference is the result of the fact that the slats will be supported by the ladder cord L when they are in the extended position EP but not when they are in the collected position CP. When the slats are in the collected position CP the slats are generally supported by the lift cord C. As the bottom rail R of the blind raises, each collected slat will change from being supported by the ladder cord L to being supported by the lift cord C.
The torsion spring may optionally be provided with a winding tab 26 proximate to a pre-loading drum 28. While the winding tab 26 and pre-loading drum 28 will rotate with the torsion spring, they have no particular function during the ordinary use of the blind. However, these structures serve to simplify the assembly of the components into a head rail H. The function of these features is described in more detail in a discussion of the assembly and use of a blind that follows herein.
As a result of the functioning of the spring means and the tendency of the slats S to return to the collected position CP after being moved to an extended position EP, the blind is unbalanced. To compensate for the unbalanced nature of the blind, a brake means 8 is provided. The brake means prevents the force stored in the spring means from retracting the slats S until retraction is desired. The brake means also impedes or prevents the lift cord or slender lifting material from being pulled from the gathering means on the shaft unless the brake means is disengaged.
The details of a preferred embodiment of the brake means 8 are illustrated in
Although the embodiment of
In a blind of the invention where both tilting and lifting are controlled, the interface of the tilter control may be combined with interface for the brake means to provide a common control interface. With such an interface, a user can operate the vertical movement or lift of the slats as well as the tilt of the slats with a single control. In the preferred embodiment of this control both the tilting and braking functions are operated with a single wand W. The combination of these controls including a brake means is depicted in
The coupling portions 50, 52, are provided with complementary jagged surfaces such that when the fixed coupling portion 48 is seated with the rotatable coupling portion 50 rotation of the brake coupling 46 is prevented. A coupling spring 54 is mounted, for exmple, to the head rail H and the rotatable coupling portion 50 to provide a seating force that will serve to return the rotatable coupling portion to its seated engagement with the fixed coupling portion 48 after disengagement. When the couplings are engaged, the control is in a braked position as shown in FIG. 11A.
As illustrated in
The length of the rod 52, the configuration and depth of the groove of the helical gear 56 and the positioning of the components are coordinated to provide different control responses depending on the positioning of the rod 52. Optionally, grooves 62 in the rod 52 in conjunction with a ball bearing 64 serve as a tactile feedback means to provide tactile feedback to the user to identify the different control positions when using the wand or rod as the ball bearing snaps into a groove with the assistance of a bearing spring 65 pressing against the ball bearing 64. These aspects of the invention are illustrated by the different positions of the rod 52 in
In
As illustrated in
The positioning of the rod 52 shown in
Those skilled in the art will recognize that this multi-position, multi-control device can be constructed to disengage the brake means by pull rather than push. Optionally, the control components may be provided in a combined structure within a separate housing (as illustrated in
In regard to the use and assembly of the unbalance blind as disclosed herein, it has been determined that a most advantageous performance of the unbalanced blind can be achieved if the spring means 4 is assembled and the spring is loaded with a stored force. This stored force preferably exists with all of the slats retracted near the head rail in their collected position CP as illustrated in FIG. 2B. In this sense, the force is continuous regardless of the position of the slats. A preferred force is approximately equivalent to the force needed to maintain the stats in the raised or collected position CP, however, a lesser force may be pre-applied to the torsion spring. The selection of a desired force must be balanced against the nature of the effort that will be exerted by a user in raising or lowering the slats. A higher force will require no user effort to raise the slats. A lower force will require some effort.
To permit the loading of a desired force into the spring means during assembly of the blind, before installation, a winding means (not shown) is attached to the winding tab 26 wound around the pre-loading drum 28. The winding means may be for example, a pre-determined length of string or other flexible strip or winding strip. The blind is then assembled by installing its components into the head rail including the spring means 4, gathering means 6, shaft 2 and any optional tilting device. The slats S and bottom rail R are also combined in the extended position EP with the lift and ladder cord or lift and ladder tape depending on the gathering means 6 and tilter devices chosen. However, when the spring means 4 is installed, its fixed end 18 is not engaged to the fixed end mount 10. Optionally, the rotational end 16 may also be disengaged from the rotation reducing means 14. This prevents any undesired load from accumulating in the spring means 4 if the shaft 2 is rotated during assembly. With the spring means disengaged, the lift cord or lift tape is gathered into the head rail by rotating the shaft 2 until the bottom rail R and slats S are in the collected position CP.
Once the slats S are in the collected position CP, the rotation end 16 of the spring means 4 is coupled to the rotation reducing means 14, if not previously done during the original install of the spring means 4. The shaft 2 is then held stationary by the brake means 8 while the winding means is pulled from the pre-loading drum 28. This will result in the rotation of the spring means 4 a certain number of turns that is equivalent to the pre-determined length of the winding means. The spring means 4 is then coupled to the fixed end mount 10 at its fixed end 18 without releasing the spring means 4 to maintain the stored force in the completed assembly. The winding means may then be removed or cut from the winding tab 26. Those skilled in the art will recognize that by changing the length of the winding means, different loads may be pre-set into the spring means 4 to supply the correct force needed to accommodate the particular weight and number of the slats S that will be used for the particular application of the blind. The method is the same for a window covering without slats such as a shade, with the exception that the covering is gathered to the head rail because of the absence of the slats.
With the stored force in the blind and installed for use in a window, a user can simply operate the shade by pulling (or pushing) the wand W to release the brake means 8. The bottom rail R can then be manually pulled down to lower the blind to any intermediate position or to the extended position EP with little effort. When the wand W is released the brake means 8 will engage and the blind will remain in the selected position. The blind can be easily raised to the collected position CP with the assistance of the spring means 4 by again releasing the brake means 8 by operation of the wand W.
Depending on which tilter device is installed into the head rail, the bottom rail R may be manually tilted to tilt the slats S when the brake means 8 is released. Alternatively, a traditional wand independent from the brake means 8 may be provided to tilt the slats S. In the embodiment with the mono control tilt brake of
While the invention has been described with regard to various embodiments, it is to be understood that the features are merely illustrative of the principles of the invention. Those skilled in the art would understand that other variations can be made without departing with the spirit and scope of the invention as defined by the claims. For example, rather than utilizing a torsion spring a power spring may be configured to provide the desired lift or retraction force for the slats of the blind. An example of a power spring would include a blade spring having a roll of flat elongated material with one end moving with the shaft and one end fixed relative to the head rail. Those skilled in the art will also recognize, for example, that only some of the components may be utilized to provide a blind with lift control but without tilt control. Similarly, while cords are used in the preferred embodiment, it is understood that such a cord is a slender length of flexible material usable for winding or gathering or supporting the slats. Another such slender flexible material includes, for example, a lift tape or lift material that may be wound on a tape spool. Tape may be configured to form a tape ladder or ladder material. One use of tape as a substitute for a cord is illustrated in
This application claims the priority filing date of U.S. provisional patent applications Ser. Nos. 60/366,502 and 60/366,501 filed on Mar. 20, 2002.
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