Patent Application
20130333849
1. Field of the Invention
The present invention relates to a window treatment having covering material extending from a headrail to a bottom bar, and more specifically, to a window treatment mechanisms allowing for easy leveling of the bottom bar without the use or tools or disassembling the window treatment.
2. Description of the Related Art
Window treatments typically include a flexible fabric or other means for covering a window in order to block or limit the daylight entering a space and to provide privacy. The window treatments for some covering materials, such as, cellular shades, Roman shades, and Venentian blinds, include two parallel lift cords extending from a bottom bar to spools on a drive shift around which the lift cords are adapted to wrap. The drive shaft may be rotated in a first rotational direction to wrap the lift cords around the spools and thus raise the bottom bar. The covering material collects on top of the bar as the bottom bar is raised, thus exposing the window and allowing daylight to enter the space. The drive shaft may be rotated in a second rotational direction to unwrap the lift cords from around the spools and thus lower the bottom bar.
If the amounts of the lift cords that extend from the bottom bar to the respective spools on the drive shaft are different from one another, the bottom bar may appear unlevel to an observer when viewed from the inside or the outside of the window. Accordingly, it is desirable to adjust the amount of the lift cords that extend between the spools on the drive shaft and the bottom bar to be able to level the bottom bar. However, prior art methods of leveling the bottom bar involved difficult and/or inaccurate procedures and sometimes required the bottom bar to be unassembled, which often required the use of tools. Therefore, there is a need for a simple method of leveling the bottom bar of a window treatment having two parallel lift cords.
The present invention provides a window treatment having mechanisms allowing for easy leveling of a bottom bar of the window treatment without the use of tools and without requiring any portion of the window treatment to be disassembled. The mechanisms allow for incremental adjustment of the amounts of each of two lift cords that extend from the bottom bar to a headrail of the motorized window treatment to thus provide fine-tuning adjustment of the levelness of the bottom bar. The mechanisms are hidden from view on the sides of the bottom bar, such that the mechanisms do not detract from the attractive, aesthetically pleasing appearance of the window treatment.
According to an embodiment of the present invention, a window treatment comprises: (1) a covering material having a top end and a bottom end; (2) a bottom bar coupled to the covering material at the bottom end; (3) a drive shaft located adjacent the top end of the covering material; (4) a lift cord rotatably received around the drive shaft and extending to the bottom bar, such that rotations of the drive shaft in first and second directions respectively raise and lower the covering material; and (5) a lift cord adjustment mechanism comprising a pulley having a circumferential groove and rotatably coupled with respect to the bottom bar. The lift cord extends from the drive shaft to the groove and wraps around the pulley in the groove, such that the amount of the lift cord that extends from the drive shaft to the lift cord adjustment mechanism may be adjusted in response to rotations of the pulley of the lift cord adjustment mechanism.
In addition, a lift cord adjustment mechanism for a window treatment is also described herein. The window treatment has a covering material and a lift cord that is rotatably received around a drive shaft and extends to a bottom bar of the window treatment, such that rotations of the drive shaft in first and second directions respectively raise and lower the covering material. The lift cord adjustment mechanism comprises a compartment having a bump arranged on a surface of the compartment, and a pulley rotatably received in the compartment. The pulley has a circumferential groove surrounded by two flanges, and is arranged in the compartment such that the periphery of the flanges may be actuated by a user to rotate the pulley. At least one of the flanges has teeth lining the circumference of the flange, and the bump is adapted to be received between two adjacent teeth of the one of the flanges. The lift cord is adapted to be received in the groove and wrap around the pulley, such that the amount of the lift cord that extends from the drive shaft to the lift cord adjustment mechanism may be adjusted in response to rotations of the pulley of the lift cord adjustment mechanism.
According to another embodiment of the present invention, a window treatment comprises: (1) a covering material extending longitudinally from a top end to a bottom end; (2) a bottom bar coupled to the bottom end of the covering material, the bottom bar extending laterally across the bottom end of the covering material between two opposite bar ends; (3) a drive shaft positioned laterally adjacent the top end of the covering material; (4) a lift cord rotatably received around the drive shaft and extending to the bottom bar, such that rotations of the drive shaft in first and second directions respectively raise and lower the covering material; and (5) a lift cord adjustment mechanism located at one of the bar ends of the bottom bar, the lift cord extending from the drive shaft to the lift cord adjustment mechanism. The lift cord adjustment mechanism is operable to adjust the amount of the lift cord that extends from the drive shaft to the lift cord adjustment mechanism in response to user actuations of the lift cord adjustment mechanism.
Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings.
The invention will now be described in greater detail in the following detailed description with reference to the drawings in which:
The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment that is presently preferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed.
The battery-powered motorized window treatment 110 also comprises a plurality of batteries 138 (e.g., four D-cell batteries), which are electrically coupled in series. The series-combination of the batteries 138 is coupled to the motor drive unit 120 for powering the motor drive unit. The batteries 138 are housed inside the headrail 114 and thus out of view of a user of the motorized window treatment 110. Specifically, the batteries 138 are mounted in two battery holders 139 located inside the headrail 114, such that there are two batteries in each battery holder as shown in
The motorized window treatment 110 further comprises lift cord adjustment mechanisms 140 located in the ends of the bottom bar 116. The lift cords 130 extend from the respective lift cord spools 134 to the respective lift cord adjustment mechanisms 140 as shown in
The endcap 150 is received into the end of the bottom bar 116, which includes a lift cord channel 158 for receiving the portion of the lift cord 130 that extends to the respective lift cord spool 134. The lift cord 130 extends through openings 156 in the compartment 148 of the endcap 150, and is received in the groove 146 in the pulley 142. The lift cord 130 wraps halfway around the pulley 142 once, such that the second end 130B of the lift cord extends into the lift cord channel 158 of the bottom bar 116. The second end 130B of the lift cord may be tied in a knot to prevent the second end of the lift cord from coming free of the groove 146 if the pulley 142 is rotated too much in one direction. Alternatively, the second end 130B of each lift cord 130 could be attached to the pulley 142, such that the lift cord is operable to wrap around the pulley in the groove as the pulley is rotated. A user is able to rotate the pulley 142 to adjust the amount of the respective lift cord 130 that extends from the pulley to the respective lift cord spool 134. The endcap 150 comprises a recess 159 surrounding a portion of the periphery of the flanges 144, such that the flanges may be easily actuated by the user to rotate the rotate the pulley 142.
When the pulley 142 is rotated by the user, the teeth of the lower flange 144 contact the bump 162, such that the pulley 142 is forced away from the rear surface 164 of the compartment 148. The axle portions 152 of the pulley 142 are able to move through the slots 154 to allow the pulley to move away from the rear surface 164 of the compartment 148, such that the teeth of the flange 144 are decoupled from the bump 162. After one of the teeth (i.e., a tooth) moves across the bump 162 as the pulley 142 is rotated, the pulley can then come to rest with the bump located between the next two teeth of the flange 144. Accordingly, the lift cord adjustment mechanisms 140 allow for incremental adjustment of the amount of the lift cords 130 that extend from the respective lift cord spools 134 to the lift cord adjustment mechanism to thus provide fine-tuning adjustment of the levelness of the bottom bar 116.
When the motor drive unit 120 rotates the drive shafts 132 to adjust the position of the bottom bar 116, the lift cord 130 contacts the cylindrical portion 160 of the pulley 142 to pull the pulley towards the rear surface 164 of the compartment 148. Since the bump 162 is located between two of the adjacent teeth of the flanges 144, the pulley 142 does not rotate as the bottom bar 116 is raised and lowered. In addition, the lift cord 130 is pinched between the wedges 166 and the cylindrical portion 160 in the groove 146, such that the lift cord 130 is held in place and does not slip through the groove. When the pulley 142 is rotated causing the pulley to move away from the rear surface 164 of the compartment 148, the lift cord 130 is no longer pinched between the cylindrical portion 160 of the pulley and the wedges 166 in the groove 146, such that the lift cord 130 may move with the pulley as the pulley is rotated.
Rather than being located in the ends of the bottom bar 116, the lift cord mechanisms 140 could alternatively be located on the bottom of the bottom bar, for example, below the location where the lift cords 130 extend down to the bottom bar from the lift cord spools 136. In addition, the motorized window treatment 100 could comprise a single lift cord mechanism 140.
While the present invention has been described with reference to the battery-powered motorized window treatment 110 having the motor drive unit 120 powered by the batteries 138, the concepts of the present invention could be applied to window treatments having manual drive systems or having motor drive units powered by external power sources, such as a direct-current (DC) power source or an alternating-current (AC) power source.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
