Patent Publication Number: US-2016245017-A1

Title: Drive system for a cordless blind

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority of U.S. provisional application No. 62/120,237, filed Feb. 24, 2015, the contents of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to the lift system of window covering. More particularly, the present invention relates to mechanisms for operating blinds, cellular shades, and roman shades. 
     Conventional window treatments, such as louvered blinds presently on the market typically use a pull cord to raise or lower blind. These cords extend from a front face of the operating mechanism and dangle, presenting an attractive nuisance for small children. The attraction becomes more pronounced when the window treatment is in the raised position, when a greater length of the cord is withdrawn and dangles within the reach of children. Regrettably, these lift cords can present a danger to small children, particularly for inadvertent strangulation. 
     As can be seen, there is a need for an improved lifting mechanism for louvered blinds and window treatments that eliminate strangulation hazards for small children. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, blind for a window or other opening comprises: a top rail having a channel formed therein; a bottom rail; a plurality of slats disposed between the top rail and the bottom rail; a lift cord having a first end operatively attached to the bottom rail and received through an aperture defined through each of the plurality of slats; and an actuator having a spring tensioned spool operatively attached to a second end of the lift cord and adapted for alternately winding and unwinding the lift cord as the blind is moved between an extended position to a retracted position. The actuator may further include an actuator housing; a shaft extending between an internal surface of the actuator housing; and the spring tensioned spool is contained within the actuator housing for rotation about the shaft. The spring tensioned spool may have a cavity defined therein containing a spring operatively coupled between the spool and the shaft. The spring may be a tape spring. In some embodiments, the spring tensioned spool has a lift cord slot defined in a portion of an outer surface of the spool. In other embodiments, the spring tensioned spool has a lift cord slot defined in a substantial portion of an outer surface of the spool. The lift cord slot may also be divided by an annular plate. 
     In other aspects of the invention, the blind may further comprise: a tilt cord operatively connected between a forward portion of the bottom rail, an aft portion of the bottom rail, and a tilt drum; and a tilt rod operable to rotate the tilt drum and impart a tilting in the bottom rail. The blind may further include a plurality of spaced apart holes defined in a forward portion and an aft portion of the plurality of slats; wherein the tilt cord is received through the plurality of spaced apart holes; and the plurality of slats tilt in unison with a rotation of the tilt drum. 
     In yet other aspects of the invention a blind comprises: a plurality of slats disposed between a top rail and a bottom rail; a lift cord having a first end operatively attached to the bottom rail and received through an aperture defined through each of the plurality of slats; and a spring tensioned actuator operatively attached to a second end of the lift cord and adapted for alternately winding and unwinding the lift cord about a spool as the blind is moved between an extended position to a retracted position. The actuator may further include an actuator housing; a shaft extending within the actuator housing, wherein the spool received on and is rotatable about the shaft; a spring received in a cavity defined within the spool; and the spring is operatively coupled between the spool and the shaft. The spring may be a tape spring. In some embodiment, the spool has a lift cord slot defined across a portion of an outer surface of the spool. In other embodiments, the spool has a lift cord slot defined across a substantial portion of an outer surface of the spool. In other embodiments, the lift cord slot is divided by an annular plate. 
     In yet another aspect of the invention, an actuator for a window treatment blind, is provided which includes: an actuator housing; a spool adapted for rotation about a shaft within the actuator housing; an aperture in an outer surface of the actuator housing adapted to receive a lift cord for positioning the window treatment blind between a retracted position and an extended position; and a spring operably attached between the spool and the shaft, wherein the spring is placed under tension with the window treatment positioned in the extended position. The spring may be placed under a reduced tension with the window treatment positioned in the retracted position. The lift cord is substantially contained within the actuator in the retracted position. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a detail perspective view of the invention shown in retracted configuration. 
         FIG. 2  is a detail perspective view shown in expanded configuration. 
         FIG. 3  is a detail perspective view of the invention. 
         FIG. 4  is a detail exploded view of the invention component item  10  actuator. 
         FIG. 5  is a section detail view of the invention along line  5 - 5  in  FIG. 1 . 
         FIG. 6  is a section detail view of the invention along line  6 - 6  in  FIG. 2 . 
         FIG. 7  is a section detail view of the invention along line  7 - 7  in  FIG. 5 . 
         FIG. 8  is a section detail view of an alternate embodiment of the invention. 
         FIG. 9  is a section detail view of an alternate embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     Broadly, an embodiment of the present invention provides a drive system and a window treatment blind that provides for cordless operation of the blind in that the blind may be moved between a retracted position and an extended position without the typical user activation of a lift cord. The drive system includes an actuator with a spring tensioned spool that winds the lift cord as the blind is retracted and unwinds the lift cord as the blind is extended. Because the lift cord is contained on the spool, the drive system eliminates the strangulation hazard to children presented by conventional lift cords. 
     As best seen in reference to  FIG. 1  a blind according to the present invention is shown in a retracted position in which the blind is retracted to permit visibility through a substantial portion of a window or opening for which it is intended to cover. The blind may include a top, or head rail  54 , and a bottom rail  52 . The head rail  54  is configured to contain the actuator and other operating components of a window blind of the present invention. A plurality of movable louvers, or slats  52 , are disposed between the top rail  54  and the bottom rail  52 . As seen in reference to  FIG. 2 , the blind is shown in an extended position in which the blind and the plurality of slats  56  are extended to cover at least a portion of the window or opening for which it is intended to cover. 
     As will be appreciated, the blind may selectively positioned between the retracted position, the extended position, and any intermediate position there between via lift cord  50  having a first end operably connected to the bottom rail  52 , such that as the lift cord is pulled, the bottom rail  52  is raised and urges the slats  56  towards the top rail  54 . As contemplated by the present invention, the lift cord  50  is threaded through an aperture defined through a top and bottom surface of each of the plurality of slats. The threaded arrangement facilitates maintaining the vertical and lateral alignment of the slats  56  as they are moved during operation of the blind. 
     In further reference to  FIG. 3 , a second end of the lift cord  50  is routed through a lift cord aperture  66  defined in the head rail  54  and operably attached to an actuator  10  that is operable to retract and retain the lift cord  50  when the blind is moved to the retracted position and to dispense the lift cord when the blind is moved to the extended position. 
     The blind may also include a tilt mechanism that is operable to selectively position the plurality of slats  56  between a substantially horizontal position and a substantially vertical position. The tilt mechanism includes a tilt cord  64  that has a first end connected to an outer portion of the bottom rail  52  and a second end that is connected to an inner portion of the bottom rail  52 . The tilt cord  64  is routed through the slats  56  via a pair of spaced apart holes extending through an outer portion of the slats  56  and an inner portion of the slats  56 . The tilt cord  64  is also routed through the top rail  54  via a tilt rod drum hole  68  defined in the top rail. The tilt cord  64  is preferably a unitary length of cord that is retained at an intermediate point of the tilt cord  64  to a tilt rod drum  58 . 
     The tilt rod drum  58  is positioned within a tilt rod bracket  62 , and may be rotated by a tilt rod  60 , extending through a rotational axis of the tilt rod drum  58 . The tilt rod  60  is operable to rotate the tilt rod drum  58  such that the first and second ends of the tilt cord  64  are alternately raised or lowered depending upon the direction of rotation of the tilt rod drum  58 , such that the slats  56  may be selectively positioned between the horizontal and vertical positions. 
     In further reference to  FIG. 4 , the actuator  10  includes an actuator housing  12  for containing the actuator components. A lift cord hole  14  is defined through a surface of the housing  12  so that the lift cord  50  may be routed into the actuator  10 . The actuator  10  may also include an actuator housing cover  20  that coupled to the actuator housing  12  so as to contain the actuator components. 
     The actuator components may include an actuator spool body  23  having a lift cord wind slot  26  defined on a portion of the spool body  23 . The lift cord wind slot  26  is adapted to receive the lift cord  50  in a wound relation within the slot  26  as the spool is rotated. The actuator spool body  24  may be formed as a substantially hollow body defining a spring chamber  28  therein. 
     The spring chamber  28  is adapted to receive a wound spring element  46  therein. The spring element  46  has a spring hook  48  defined at a first end of the spring  46  that is operably connected to a spring hook slot  34  defined in a surface of the spool body  23 . A second end of the spring  46  is operatively attached to an actuator shaft  22  that extends within the actuator body  12 . The second end of the spring  46  may be attached to the actuator shaft  22  via a fastener  32 , such as a screw, pin, rivet, or optionally a second hook arrangement. The spring  46  may be contained within the spring chamber  28  via a spool cover  40  and a side face of the spool body  28 . 
     The spool cover  40  has a spool aperture  42  that is coaxially aligned with a rotational axis of the spool body  24 . A second spool aperture may be defined in the side face of the spool body  24  and coaxially aligned with the rotational axis of the spool body  24 . The spool cover  40  may be coupled to the end of the spool body  24  by the cooperative engagement of one or more tabs  44  extending from the spool cover  40  and a corresponding notch  36  defined in the spool body  24 . 
     As seen in reference to  FIG. 5 , the actuator  10  is depicted with the blinds in a retracted condition. In this condition, the lift cord  50  is wound about the spool  28  within the spool slot  26 . The spring element  46  is shown in a relaxed condition, which may include a partial tensioning of the spring element within the actuator so as to retain the blind in the retracted condition. 
     As seen in reference to  FIG. 6 , the actuator  10  and spring  46  depicted with the blinds in an extended condition. In this condition, the lift cord  50  is withdrawn from the spool  28  and the actuator  10 . As the lift cord  50  is withdrawn from the spool  28 , the tension on the spring element  46  is increased. The tension imparted on the spring element  46  will provide sufficient force so as to rotate the spool  28  and wind the lift cord  50  about the spool when the blind is raised. The tension should also be sufficient so as to maintain the position of the bottom rail  52  at any intermediate position between the retracted and extended position such that the blind will maintain its position as selected by a user. 
     As seen in reference to  FIG. 7 , a cross sectional view of an actuator  10  is depicted. The lift cord  50  enters the actuator  10  through a sidewall of the actuator case body  12  via the case body lift cord hole  14 . The lift cord  50  winds around the wind slot  26  of the spool body  24  so as to retract and retain the lift cord  50  within the actuator  10 . Because the lift cord  50  is retained in the actuator, the blind of the present invention avoids the presence and associated child hazards presented by conventional lift cords. 
     The actuator shaft  22  extends between the interior ends of the actuator body  12 . In the embodiment shown, the shaft  22  may be integrally formed with the actuator body cover  18  and extends and is received within a actuator shaft shaft hole  16  defined in an opposite face of the body  12 . The spool body  24  has a hub  30  which receives the shaft  22  therein for rotation of the spool body  24  about the shaft  22  during operation. As indicated, previously, the spool cover  40  may also have an aperture  42  providing a corresponding hub at an end of the spool body  24  for rotation about the shaft  22 . The spring  46  is shown within the spool spring chamber  28  and is operatively attached between the spool body  24  and the spool shaft  22 . 
     As seen in an alternative embodiment of an actuator  70 , depicted in reference to  FIG. 8 , the actuator  70  includes an actuator case body  72  to contain the components of the actuator  70 . The case body  72  may also be provided with a shaft hub  76  to receive a first end of the actuator spool shaft  82  disposed between the interior sidewalls of the case body  72 . The shaft  82  may be integrally formed with a case body cover  80  attached to an opposite end of the case body  72 . The spool  84  may have a hub  90  that receives the shaft  82  for rotation about the shaft  82 . The spool  84  may include a plurality of lift cord slots  86  separated by an annular plate between adjacent slots  86 . The slots are adapted to receive the lift cord  50  in a wound arrangement during operation of the blinds. An internal spool cavity  88  is defined to receive the spring  46 , which is operatively connected between the spool  86  and the shaft  82 . 
     As seen in a second alternative embodiment of an actuator  94  depicted in reference to  FIG. 9 , the actuator  94  includes an actuator case body  96  to contain the components of the actuator  94 . The case body  96  may also be provided with a shaft hub  98  to receive a first end of the actuator spool shaft  104  disposed between the interior sides of the case body  96 . The shaft  104  may be integrally formed with a case body cover  100  and a case body plate  102  attached to an opposite end of the case body  96 . The spool  106  may have a hub  112  that receives the shaft  104  for rotation of the spool  106  about the shaft  104 . The spool  106  may include a plurality of lift cord slots  108  separated by an annular plate between adjacent slots  108 . The slots  108  may extend across a substantial portion of the exterior surface of the spool  106 . The slots  108  are adapted to receive the lift cord  50  in a wound arrangement during operation of the blinds. The internal spool cavity  110  is defined to receive the spring  46 , which is operatively connected between the spool  106  and the shaft  104 . A spool end plate  114  may also be attached to an open end of the spool  106  to contain the spring  46  therein. 
     In operation, as a user raises the bottom rail  52  of the blind, tension applied to the spring  46  will cause the spool  24 ,  84 ,  106  to rotate about the shaft  22 ,  82 ,  104  and wind the lift cord  50  about the spool within the spool slot  26 ,  86 ,  108  within the actuator housing. Because the lift cord  50  is retained within the actuator, the free ends of the lift cord  50  that previously presented a hazard to children has been eliminated. In addition, the actuator of the present invention eliminates hides the lift cord  50  from view, thereby presenting a more attractive, cordless appearance. When the blind is lowered to the extended position, the withdrawal of the lift cord  50  from the spool as it is drawn by the bottom rail  52  imparts tension in the spring  46  so that it is once again loaded to retract the lift cord  50 . 
     It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.