Patent Abstract:
A window treatment may include one or more lift cord adjustment mechanisms for leveling of a bottom bar of the window treatment. The mechanisms may allow for fine-tuning adjustment of the levelness of the bottom bar. The mechanisms may be disposed at respective ends of the botom bar. The mechanisms may be directly accessible through the ends of the bottom bar. Each mechanism may include a pulley having a circumferential groove to receive a corresponding lift cord. A portion of the pulley may protrude relative to an exterior surface of the bottom bar. The mechanisms may be hidden from view on the sides of the bottom bar, such that the mechanisms do not detract from the appearance of the window treatment. Manual operation of a mechanism may adjust an amount of a corresponding lift cord that extends from the drive shaft to the pulley of the mechanism.

Full Description:
BACKGROUND OF THE INVENTION 
     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. 
     SUMMARY OF THE INVENTION 
     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. 
     As described herein, an example window treatment may include: (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, the drive shaft operable to raise and lower the covering material; (4) a lift cord rotatably received around the drive shaft and extending to the bottom bar, such that rotation of the drive shaft in a first direction raises the covering material, and rotation of the drive shaft in a second direction lowers the covering material; and (5) a lift cord adjustment mechanism coupled to the bottom bar, the lift cord adjustment mechanism comprising a pulley having a circumferential groove. The pulley may be rotatably coupled with respect to the bottom bar, such that a portion of the pulley protrudes relative to an exterior surface of the bottom bar. The lift cord may be secured relative to the groove, such that rotation of the pulley causes the lift cord to wrap around the pulley within the groove, thereby adjusting an amount of the lift cord that extends from the drive shaft to the lift cord adjustment mechanism. 
     An example lift cord adjustment mechanism for a window treatment is also described herein. The window treatment may include 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 may include a compartment having a bump arranged on a surface of the compartment, and a pulley rotatably received in the compartment. The pulley may define a circumferential groove surrounded by two flanges, and may be 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 may define teeth lining the circumference of the flange, and the bump may be adapted to be received between two adjacent teeth of the one of the flanges. The lift cord may be adapted to be received in the groove and wrap around the pulley, such that an 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. 
     As further described herein, an example window treatment may include: (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 adjacent the top end of the covering material; the drive shaft operable to raise and lower the covering material; (4) a lift cord rotatably received around the drive shaft and extending to the bottom bar, such that rotation of the drive shaft in a first direction raises the covering material, and rotation of the drive shaft in a second direction lowers the covering material; and (5) a lift cord adjustment mechanism that is configured to rotate about a longitudinally extending axis, the lift cord adjustment mechanism located at one of the bar ends of the bottom bar and directly accessible through the bar end, the lift cord extending from the drive shaft to the lift cord adjustment mechanism. Manual rotation of the lift cord adjustment mechanism may adjust an amount of the lift cord that extends from the drive shaft to 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described in greater detail in the following detailed description with reference to the drawings in which: 
         FIG. 1  is a perspective view of a battery-powered motorized window treatment according to an embodiment of the present invention; 
         FIG. 2  is a front view of the motorized window treatment of  FIG. 1 ; 
         FIG. 3  is an enlarged exploded perspective view of one end of a bottom bar of the motorized window treatment of  FIG. 1  showing a lift cord adjustment mechanism; 
         FIG. 4  is a top cross-sectional view of the bottom bar of the motorized window treatment of  FIG. 1 ; 
         FIG. 5  is a front perspective view of the lift cord adjustment mechanism of  FIG. 3 ; 
         FIG. 6  is a rear perspective view of the lift cord adjustment mechanism of  FIG. 3 ; 
         FIG. 7  is a front view of the lift cord adjustment mechanism of  FIG. 3 ; 
         FIG. 8  is a top cross-sectional view of the lift cord adjustment mechanism of  FIG. 3 ; 
         FIG. 9  is a bottom cross-sectional view of the lift cord adjustment mechanism of  FIG. 3 ; 
         FIG. 10  is a left side cross-sectional view of the lift cord adjustment mechanism of  FIG. 3 ; and 
         FIG. 11  is a rear cross-sectional view of the lift cord adjustment mechanism of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     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. 
       FIG. 1  is a perspective view of a battery-powered motorized window treatment  110  according to an embodiment of the present invention. The battery-powered motorized window treatment  110  comprises a covering material (e.g., a cellular shade fabric  112 ) that is adapted to hang (i.e., extend longitudinally) in front of a window and may be adjusted between a fully-open position P FULLY-OPEN  and a fully-closed position P FULLY-CLOSED  to control the amount of daylight entering a room or space. The cellular shade fabric  112  has a top end connected to a headrail  114  and a bottom end connected to a bottom bar  116  (e.g., a weighting element), which extends laterally across the bottom end of the cellular shade fabric. The motorized window treatment  110  has mounting brackets  115  for mounting the headrail  114  to a wall or a ceiling. The motorized window treatment  110  comprises a motor drive unit  120  for raising and lowering the weighting element  116  and the cellular shade fabric  112  between the fully-open position P FULLY-OPEN  and the fully-closed position P FULLY-CLOSED . By controlling the amount of the window covered by the cellular shade fabric  112 , the motorized window treatment  110  is able to control the amount of daylight entering the room. In addition, the battery-powered motorized window treatment  110  could alternatively comprise other types of covering materials, such as, for example, a plurality of horizontally-extending slats (i.e., a Venetian or Persian blind system), pleated blinds, a roller shade fabric, or a Roman shade fabric. 
       FIG. 2  is a front view of the battery-powered motorized window treatment  110  with a front portion of the headrail  114  removed to show the motor drive unit  120 , which is located in the center of the headrail. The motorized window treatment  110  comprises lift cords  130  that each comprise a first end  130 A and a second end  130 B opposite the first end. The lift cords  130  extend from the headrail  114  to the bottom bar  116  for allowing the motor drive unit  120  to raise and lower the bottom bar. The motor drive unit  120  includes an internal motor (not shown) coupled to drive shafts  132  that extend from the motor on each side of the motor and are each coupled to a respective lift cord spool  134 . The first ends  130 A of each lift cords  130  are operatively coupled to the respective drive shafts  132 , such that the lift cords  130  are windingly received around the lift cord spools  134  as the drive shafts are rotated to raise the covering material  112 . The second ends  130 B of the lift cords  130  are fixedly attached to the weighting element  116 , and the motor drive unit  120  is operable to rotate the drive shafts  132  to raise and lower the weighting element. The motorized window treatment  110  further comprises two constant-force spring assist assemblies  135 , which are each coupled to the drive shafts  132  adjacent to one of the two lift cord spools  134 . Each of the lift cord spools  134  and the adjacent constant-force spring assist assembly  135  are housed in a respective lift cord spool enclosure  136  as shown in  FIG. 2 . Alternatively, the motorized window treatment  110  could comprise a single drive shaft, which extends along the length of the headrail  114  and is coupled to both of the lift cord spools  134 , and the motor drive unit  120  could be located at either end of the headrail. 
     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  FIG. 2 . Since the motor drive unit  120  is located in the center of the headrail  114  and the drive shafts  132  extend out of both sides of the motor drive unit to the lift cord spools  134 , there is plenty of the room for the batteries  138  to be located adjacent the opposite sides of the headrail. The batteries  138  provide the motorized window treatment  110  with a practical lifetime (e.g., approximately three years), and are typical “off-the-shelf” batteries that are easy and not expensive to replace. Alternatively, the motor drive unit  120  could comprise more batteries (e.g., six or eight) coupled in series or batteries of a different kind (e.g., AA batteries) coupled in series. 
     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  FIG. 2 . The lift cord adjustment mechanisms  140  allow for adjustment of the amount of the lift cords  130  that extend from the respective lift cord spools  134  to the respective lift cord adjustment mechanisms to thus allow for adjustment of the levelness of the bottom bar  116  (when the shade fabric  112  and the bottom bar are stationary). 
       FIG. 3  is an enlarged exploded perspective view of one end of the bottom bar  116  showing one of the lift cord adjustment mechanisms  140  in greater detail.  FIG. 4  is a top cross-sectional view of the bottom bar  116  showing the lift cords  130  and the lift cord adjustment mechanisms  140 .  FIGS. 5 and 6  are front and rear perspective views, respectively, of the lift cord adjustment mechanisms  140 . The lift cord adjustment mechanisms  140  each comprise a pulley  142  (i.e., a drum) having two toothed flanges  144  (i.e., ratchet portions) surrounding a circumferential groove  146 . The pulley  142  is received in a compartment  148  of an endcap  150  and comprises cylindrical axle portions  152  about which the pulley is able to rotate. The axle potions  152  are received in slots  154  in the compartment, such that the pulley is rotatably coupled to the endcap  150 . The pulley  142  has teeth lining the circumference of the flanges  144 . 
     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  130 B of the lift cord extends into the lift cord channel  158  of the bottom bar  116 . The second end  130 B 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  130 B 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 . 
       FIG. 7  is a front view,  FIG. 8  is a top cross-sectional view,  FIG. 9  is a bottom cross-sectional view,  FIG. 10  is a left side cross-sectional view, and  FIG. 11  is a rear cross-sectional view of one of the lift cord mechanisms  140 . The pulley  142  comprises a central cylindrical portion  160  ( FIG. 9 ) located between the two flanges  144 . The lift cord  130  extends through the openings  158  and around the cylindrical portion  160  of the pulley  142 . The endcap  150  comprises a bump  162  that is located on a rear surface  164  of the compartment  148  and is received between two adjacent teeth of one of the flanges  144  of the pulley  142  as shown in  FIG. 8 . The endcap  150  also comprises wedges  166  that extend into the groove  148  of the pulley  142  when the pulley is installed in the compartment  148  as shown in  FIGS. 9 and 11 . 
     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.

Technology Classification (CPC): 4