Window covering drive system

Abstract

A window covering drive system mountable in a sash frame, such as an interior sash, for use in operating a window covering mounted to the sash. The drive system including a drive component couplable to the covering, the drive component including a belt and a belt tensioning mechanism providing pre-tension in the belt and sustaining tension during operation of the drive system. The drive system also including an operator assembly slidably mounted to the sash and coupled to the drive component, such that linear motion of the operator assembly results in movement of the belt and rotary action of the drive component to operate the covering. The drive system may include a frame connecting corner lock configured with features that couple to the drive component. Additionally, a covering operating mechanism may be included having a lift spool with a varying diameter about which a lift cord is wound and unwound.

1 . A window covering drive system mountable in a sash frame of a window for use in operating a window covering mounted to the sash frame, the drive system comprising: 
 a drive component couplable to the window covering, the drive component including a drive belt and a belt tensioning mechanism that provides pre-tension in the belt and sustains tension during operation of the drive system; and    an operator assembly slidably mounted to the sash frame and coupled to the drive component, such that linear motion of the operator assembly results in movement of the drive belt and rotary action of a portion of the drive component to operate the window covering.    
     
     
         2 . The window covering drive system of  claim 1 , wherein the drive component is positioned within a member of the sash frame.  
     
     
         3 . The window covering drive system of  claim 1 , wherein the drive component further comprises a pair of pulleys around which the drive belt is positioned, with at least one of the pair of pulleys coupled to a drive coupling configured to releasably couple to the window covering, such that movement of the drive belt results in rotation of the pair of pulleys and the drive coupling so as to operate the window covering.  
     
     
         4 . The window covering drive system of  claim 1 , wherein the drive belt comprises two ends and wherein the belt tensioning mechanism comprises a spring clamp connecting the two belt ends and applying tension between the two belt ends.  
     
     
         5 . The window covering drive system of  claim 4 , wherein the drive component further comprises a limiter that limits a gap between the two belt ends and movement of the limiter increases tension in the drive belt, such that the drive belt is pulled about a drive pulley.  
     
     
         6 . The window covering drive system of  claim 1 , wherein the operator assembly comprises a sled that slides within a channel in the sash frame and an operator handle coupled to the sled and positioned on the sash frame for use by an operator, the sled coupled to the drive component, such that sliding movement of the operator handle by an operator results in sliding movement of the sled and actuation of the drive component to operate the window covering.  
     
     
         7 . The window covering drive system of  claim 6 , wherein the drive belt comprises two ends and wherein the belt tensioning mechanism comprises a spring clamp connecting the two belt ends and applying tension between the two belt ends and wherein the sled is configured to slidably receive the spring clamp and to serve as a limiter that limits a gap between the two belt ends, such that the drive belt is pulled about a pair of pulleys to reduce slack and maintain tension in the drive belt.  
     
     
         8 . The window covering drive system of  claim 1 , wherein the sash frame comprises a plurality of members configured to connect at corners of the frame and further comprising a corner lock configured to attach to and connect two adjoining frame members at the corner of the frame, the corner lock including a recess formed to receive and couple to a portion of the drive component.  
     
     
         9 . The window covering drive system of  claim 8 , wherein the sash frame further comprises at least two corner locks and wherein the drive component further comprises a pair of pulleys about which the drive belt is positioned and wherein each of the pulleys are received by the corner locks such that each corner lock recess receives a portion of the drive belt and a pulley.  
     
     
         10 . The window covering drive system of  claim 1 , further comprising a window covering operating mechanism configured to operate the window covering through actuation of a lift cord, the operating mechanism including: 
 a drive shaft coupled to the drive component; and    a lift spool assembly coupled to the drive shaft, the lift spool assembly including a rotatable lift spool having first and second ends and a varying diameter with the diameter decreasing from the first and second ends toward a middle, the lift spool attached to a first end of the lift cord and configured to receive the lift cord in a series of coils when the lift spool rotates in one direction.    
     
     
         11 . The window covering drive system of  claim 10 , wherein the lift spool assembly further comprises a housing supporting the lift spool, the housing including an angled surface positioned to engage the lift cord as it first winds about the lift spool at the second end of the lift spool and to urge the lift cord coil away from the second end toward the middle of the spool so as to make room for a subsequent coil of the lift cord as the lift spool continues to rotate.  
     
     
         12 . The window covering drive system of  claim 1  in combination with a window or window sash including the sash frame and a glazing panel mounted therein.  
     
     
         13 . The window covering drive system of  claim 12 , wherein the sash frame is openable with respect to the window or window sash and wherein the sash frame comprises an opening restrictor mounted to the openable sash frame on one end and to the window or window sash on the other end, the opening restrictor restricting the openability of the openable frame.  
     
     
         14 . The window or sash of  claim 13 , wherein the openable sash frame rotates to swing open and shut with respect to the window or window sash, and wherein the opening restrictor comprises: 
 a first cord anchor mounted to the openable sash frame;    a second cord anchor mounted to the window or window sash;    a spring anchor mounted to the openable sash frame at an opposite end than the first cord anchor;    a slider slidably mounted to the openable sash frame between the first cord anchor and the spring anchor and resiliently coupled to the spring anchor by a resilient member; and    a cord connected to the first cord anchor at a first cord end, routed around the slider and connected to the second cord anchor at a second cord end,    such that opening movement of the openable sash frame results in extension of the cord away from the window or window sash with a corresponding movement of the slider toward the first cord anchor and away from the spring anchor causing an extension of the resilient member.    
     
     
         15 . A window covering drive system mountable in a sash frame for use in operating a window covering mounted to the sash frame, the sash frame formed from a plurality of frame members connected together at corners of the frame, the drive system comprising: 
 a drive component couplable to the window covering;    a corner lock configured to attach to and connect two adjoining frame members at the corner of the sash frame, the corner lock including a recess formed to receive and couple to a portion of the drive component; and    an operator assembly slidably mounted to the sash frame and coupled to the drive component, such that linear motion of the operator assembly results in rotary action of a portion of the drive component to operate the window covering.    
     
     
         16 . The window covering drive system of  claim 15 , wherein the drive component comprises a drive belt and first and second pulleys about which the drive belt is positioned, with the first pulley mounted within the recess of the corner lock and a portion of the drive belt passing within the recess and about the first pulley.  
     
     
         17 . The window covering drive system of  claim 16 , further comprising another corner lock configured to attach to and connect two adjoining frame members at the corner of the sash frame, the corner lock including a recess formed to receive and couple to the second pulley with a portion of the drive belt passing within the recess and about the second pulley.  
     
     
         18 . The window covering drive system of  claim 15 , further comprising a window covering operating mechanism configured to operate the window covering through actuation of a lift cord, the operating mechanism including: 
 a drive shaft coupled to the drive component at the corner lock; and    a lift spool assembly coupled to the drive shaft, the lift spool assembly including a rotatable lift spool having first and second ends and a varying diameter with the diameter decreasing from the first and second ends toward a middle, the lift spool attached to a first end of the lift cord and configured to receive the lift cord in a series of coils when the lift spool rotates in a first direction.    
     
     
         19 . The window covering drive system of  claim 18 , wherein the lift spool assembly further comprises a housing supporting the lift spool, the housing including an angled surface positioned to engage the lift cord as it first winds about the lift spool at the second end of the lift spool and to urge the lift cord coil away from the second end toward the middle of the spool so as to make room for a subsequent coil of the lift cord as the lift spool continues to rotate.  
     
     
         20 . The window covering drive system of  claim 18 , wherein the drive component further comprises a shaft coupling housed within the corner lock and coupled to the drive shaft.  
     
     
         21 . The window covering drive system of  claim 15 , wherein the drive component further comprises a drive belt and a belt tensioning mechanism that provides pre-tension in the belt and sustains tension during operation of the drive system.  
     
     
         22 . The window covering drive system of  claim 21 , wherein the drive belt comprises two ends and wherein the belt tensioning mechanism comprises belt clamps connecting the two belt ends and a spring applying tension between the two belt ends.  
     
     
         23 . The window covering drive system of  claim 22 , wherein the drive component further comprises a limiter that limits a gap between the two belt ends, such that initial motion of the operator handle does not produce motion of the drive belt until the limiter is engaged and such that the drive belt is pulled about a pair of pulleys to reduce slack and maintain tension in the drive belt.  
     
     
         24 . The window covering drive system of  claim 21 , wherein the operator assembly comprises a sled that slides within a channel in the sash frame and an operator handle coupled to the sled and positioned on the sash frame for use by an operator, with the sled coupled to the drive component, such that sliding movement of the operator handle by an operator results in sliding movement of the sled and actuation of the drive component for operation of the window covering, and wherein the drive belt comprises two ends and the belt tensioning mechanism comprises belt clamps connecting the two belt ends and a spring applying tension between the two belt ends, and wherein the sled is configured to slidably receive the spring clamp with the operator handle configured to serve as a limiter that limits a gap between the two belt ends, such that initial motion of the operator handle does not produce motion of the drive belt until the belt clamp engages the sled resulting in the drive belt being pulled about a pair of pulleys to reduce slack and maintain tension in the drive belt.  
     
     
         25 . The window covering drive system of  claim 15  in combination with a window or window sash including the sash frame and a glazing panel mounted therein.  
     
     
         26 . The window covering drive system of  claim 25 , wherein the sash frame is openable with respect to the window or window sash and wherein the sash frame comprises an opening restrictor mounted to the openable sash frame on one end and to the window or window sash on the other end that restricts the openability of the openable sash frame.  
     
     
         27 . The window or sash of  claim 26 , wherein the openable sash frame rotates to swing open and shut with respect to the window or window sash, and wherein the opening restrictor comprises: 
 a first cord anchor mounted to the openable sash frame;    a second cord anchor mounted to the window or window sash;    a spring anchor mounted to the openable sash frame at an opposite end than the first cord anchor;    a slider slidably mounted to the openable sash frame between the first cord anchor and the spring anchor and resiliently coupled to the spring anchor by a resilient member; and    a cord connected to the first cord anchor at a first cord end, routed around the slider and connected to the second cord anchor at a second cord end,    such that opening movement of the openable sash frame results in extension of the cord away from the window or window sash with a corresponding movement of the slider toward the first cord anchor and away from the spring anchor causing an extension of the resilient member.    
     
     
         28 . A window covering drive system mountable in a sash frame for use in operating a window covering mounted to the sash frame, the drive system comprising: 
 a window covering operating mechanism configured to operate the window covering through actuation of a lift cord, the operating mechanism including a drive shaft and a lift spool assembly coupled to the drive shaft, the lift spool assembly including a rotatable lift spool having first and second ends and a varying diameter with the diameter decreasing from the first and second ends toward a middle, the lift spool attached to a first end of the lift cord and configured to receive the lift cord in a series of coils when the lift spool rotates in a first direction;    a drive component coupled to the drive shaft of the window covering operating mechanism; and    an operator assembly slidably mounted to the sash frame and coupled to the drive component, such that linear motion of the operator assembly results in rotary action of a portion of the drive component to rotate the drive shaft and operate the window covering operating mechanism.    
     
     
         29 . The window covering drive system of  claim 28 , wherein the lift spool assembly further comprises a housing supporting the lift spool, the housing including an angled surface positioned to engage the lift cord as it first winds about the lift spool at the second end of the lift spool and to urge the lift cord coil away from the second end toward the middle of the spool so as to make room for a subsequent coil of the lift cord as the lift spool continues to rotate.  
     
     
         30 . The window covering drive system of  claim 29 , wherein rotation of the lift spool in a second direction results in uncoiling of the lift cord from about the lift spool.  
     
     
         31 . The window covering drive system of  claim 28 , wherein the drive component further comprises a drive belt and a belt tensioning mechanism that provides pre-tension in the belt and sustains tension during operation of the drive system.  
     
     
         32 . The window covering drive system of  claim 31 , wherein the drive belt comprises two ends and wherein the belt tensioning mechanism comprises a spring clamp connecting the two belt ends and applying tension between the two belt ends, the spring clamp including two belt clamps attached to the two belt ends, respectively, and a spring connected between the two belt clamps.  
     
     
         33 . The window covering drive system of  claim 32 , wherein the drive component further comprises a limiter that limits a gap between the two belt ends, such that initial motion of the operator handle does not produce motion of the drive belt until the limiter is engaged and such that the drive belt is pulled about a pair of pulleys to reduce slack and maintain tension in the drive belt.  
     
     
         34 . The window covering drive system of  claim 31 , wherein the operator assembly comprises a sled that slides within a channel in the sash frame and an operator handle coupled to the sled and positioned on the sash frame for use by an operator, with the sled coupled to the drive component, such that sliding movement of the operator handle by an operator results in sliding movement of the sled and actuation of the drive component that operates the window covering, and wherein the drive belt comprises two ends and the belt tensioning mechanism comprises a spring clamp connecting the two belt ends and applying tension between the two belt ends, and wherein the sled is configured to slidably receive the spring clamp and the operator handle is configured to serve as a limiter that limits a gap between the two belt ends, such that initial motion of the operator handle does not produce motion of the drive belt until the spring clamp engages the sled and such that the drive belt is pulled about a pair of pulleys to reduce slack and maintain tension in the drive belt.  
     
     
         35 . The window covering drive system of  claim 28 , wherein the sash frame comprises a plurality of members configured to connect at corners of the sash frame and further comprising a corner lock configured to attach to and connect two adjoining frame members at the corner of the sash frame, the corner lock including a recess formed to receive and couple to a portion of the drive component.  
     
     
         36 . The window covering drive system of  claim 35 , wherein the drive component comprises a drive belt and first and second pulleys about which the drive belt is positioned, with the first pulley received within the recess of the corner lock and a portion of the drive belt passing within the recess and about the first pulley.  
     
     
         37 . The window covering drive system of  claim 28  in combination with a window or window sash including the sash frame and a glazing panel mounted therein.  
     
     
         38 . The window covering drive system of  claim 37 , wherein the sash frame is openable with respect to the window or window sash and wherein the sash frame comprises an opening restrictor mounted to the openable sash frame on one end and to the window or window sash on the other end that restricts the openability of the openable sash frame.  
     
     
         39 . The window or sash of  claim 38 , wherein the openable sash frame rotates to swing open and shut with respect to the window or window sash, and wherein the opening restrictor comprises: 
 a first cord anchor mounted to the openable sash frame;    a second cord anchor mounted to the window or window sash;    a spring anchor mounted to the openable sash frame at an opposite end than the first cord anchor;    a slider slidably mounted to the openable sash frame between the first cord anchor and the spring anchor and resiliently coupled to the spring anchor by a resilient member; and    a cord connected to the first cord anchor at a first cord end, routed around the slider and connected to the second cord anchor at a second cord end,    such that opening movement of the openable sash frame results in extension of the cord away from the window or window sash with a corresponding movement of the slider toward the first cord anchor and away from the spring anchor causing an extension of the resilient member.    
     
     
         40 . A method of operating a window covering mounted to a sash frame, the sash frame including a drive system coupled to the window covering and a handle coupled to the sash frame and to the drive system, the method comprising the steps of: 
 sliding the handle along a portion of the sash frame;    engaging the handle with the drive system;    moving a portion of the drive system by continued sliding of the handle resulting in rotation of a drive component operationally coupled between the window covering and the drive system; and    adjusting the window covering in a desired manner including at least one of extending, contracting, tilting open and tilting closed by movement of the handle.