Motorized window shade system

Abstract

A quiet motorized window shade assembly mountable within a window frame includes a flexible shade and an elongated roller. An end of the shade is retained on the roller for winding of the shade on the roller. The window shade assembly further includes a drive system located externally of the roller. The drive system includes a motor and a drive shaft having a central axis parallel to a central axis of the roller. The drive shaft is connected to an acoustically lossy drive belt supported by drive and roller pulleys to transfer rotation of the drive shaft to rotation of the roller. The roller and drive belt substantially span a distance that separates opposing surfaces of the window frame to provide minimal distances between the window frame and the shade.

What is claimed is:  
     
         1 . A motorized shade assembly for use within a window frame having opposing frame surfaces, the shade assembly comprising: 
 a flexible shade having opposite edges;    an elongated roller having a central axis and supported within the window frame for rotation about the central axis, the roller defining a winding surface and retaining an end of the flexible shade for winding receipt of the shade;    a drive system located externally of said elongated roller and having a motor and a drive shaft rotatably driven by the motor, said drive shaft having a central axis, the drive system supported adjacent an end of the elongated roller such that the central axis of the drive shaft is substantially parallel to the central axis of the roller; and    a drive belt defining an endless loop, the drive belt supported at a first location to operably engage the drive shaft of the drive system and at a second location to operably engage the roller adjacent the winding surface such that the rotation of the drive shaft results in rotation of the roller,    the roller and drive belt substantially spanning the distance between the opposing surfaces of the window frame to provide for minimal distance between the opposing surfaces of the window frame and the respective opposite edges of the flexible shade.    
     
     
         2 . The motorized shade assembly according to  claim 1  wherein the minimal distance is independent of the size of the drive system.  
     
     
         3 . The motorized shade assembly according to  claim 1  wherein the minimal distance at the drive system end of the elongated roller is less than about 1 inch between the window frame surface and the respective flexible shade edge.  
     
     
         4 . The motorized shade assembly according to  claim 1 , further comprising a first drive transfer member supported for rotation about a central axis, the drive transfer member coupled to the roller for coaxial rotation therewith, the drive belt engaging the drive transfer member to transfer rotation of the drive motor shaft to rotation of the roller.  
     
     
         5 . The motorized shade assembly according to  claim 4 , wherein the drive transfer member comprises a cylindrical portion defining an outer surface adapted for engagement with an inner surface of the drive belt.  
     
     
         6 . The motorized shade assembly according to  claim 5 , wherein the drive transfer member further comprises a post extending from the cylindrical portion, the post having an outer surface adapted for interfit within an opening in a drive coupler secured to the roller, the interfit between the post and the opening providing for torque transfer between the first drive transfer member and the roller.  
     
     
         7 . The motorized shade assembly according to  claim 5 , wherein the outer surface of the cylindrical portion of the first drive transfer member includes spaced notches, and wherein the inner surface of the drive belt includes spaced teeth, the spacing of the drive belt teeth being substantially equal to the spacing of the notches of the first drive transfer member to facilitate engagement therebetween.  
     
     
         8 . The motorized shade assembly according to  claim 4 , further comprising a second drive transfer member having a central axis, the second drive transfer member secured to the drive shaft for coaxial rotation therewith, the drive belt engaging the second drive transfer member to transfer rotation of the drive shaft to rotation of the elongated roller.  
     
     
         9 . The motorized shade assembly according to  claim 7 , further comprising a second drive transfer member having a central axis, the second drive member secured to the drive shaft for coaxial rotation therewith, the second drive transfer member comprising a cylindrical portion having a notched outer surface, the notches of the second drive transfer member having a spacing that is substantially equal to the spacing of the drive belt teeth to facilitate engagement therebetween.  
     
     
         10 . A window shade drive assembly for use within a window frame having opposing frame surfaces, the window shade drive assembly comprising: 
 an elongated roller supported for rotation about a central axis and adapted for winding and unwinding a flexible shade having opposite edges upon rotation of the roller;    a drive system located externally of said elongated roller having a motor and a drive shaft rotatably driven by said motor, said drive shaft having a central axis, the drive system supported such that the drive shaft central axis is substantially parallel to the roller central axis;    a drive belt operably connected to the drive shaft such that the drive belt is driven by the drive shaft; and    a first drive transfer member having a central axis, the first drive transfer member coupled to an end of the elongated roller for coaxial rotation therewith,    the elongated roller and the first drive transfer member extending between opposing frame surfaces of the window frame and substantially spanning a distance therebetween to provide for minimization of the size of the gaps between the opposing surfaces of the window frame and the respective opposite edges of a shade supported by the roller.    
     
     
         11 . The motorized shade assembly according to  claim 10  wherein the sizes of the gaps are independent of the size of the drive system.  
     
     
         12 . The motorized shade assembly according to  claim 10  wherein the sizes of the gaps are less than about 1 inch.  
     
     
         13 . The window shade drive assembly according to  claim 10 , further comprising a second drive transfer member having a central axis, the second drive transfer member secured to the drive shaft for rotation therewith, the drive belt engaging the second drive transfer member to be driven thereby.  
     
     
         14 . The window shade drive assembly according to  claim 13 , wherein each of the first and second drive transfer members includes a substantially cylindrical member defining an outer surface that engages an inner surface of the drive belt to transfer rotation of the drive shaft to rotation of the elongated roller.  
     
     
         15 . The window shade drive assembly according to  claim 14 , wherein the outer surface of the first drive transfer member has a diameter that is less than a diameter of the outer surface of the second drive transfer member, the difference in the diameters providing for decreased rotational speed for the drive shaft for a given rotational speed for the roller thereby reducing noise.  
     
     
         16 . The window shade drive assembly according to  claim 14 , comprising first and second elongated rollers each having a central axis, the central axis of the second elongated roller offset from the central axis of the first elongated roller to provide for support of inner and outer shades with respect to the frame of the window.  
     
     
         17 . The window shade drive assembly according to  claim 16 , wherein the first and second elongated rollers are positioned between opposing first and second frame surfaces of the window frame, the drive assembly comprising first and second drive systems for driving the first and second elongated rollers, respectively, and wherein the first drive system is adapted for support adjacent the first frame surface and the second drive system is adapted for support adjacent the second frame surface.  
     
     
         18 . A motor driven shade assembly for use within a window frame having opposing frame surfaces, the motor driven shade assembly comprising: 
 a flexible shade having opposite edges;    an elongated roller supported for rotation about a central axis, the elongated roller adapted for winding receipt of the flexible shade;    a drive transfer member having a central axis, the drive transfer member coupled to an end of the elongated roller to provide for torque transfer from the drive transfer member to the elongated roller; and    a flexible drive belt engaging an outer surface of the drive transfer member to transfer rotation to the roller from a drive shaft having a central axis that is offset from the roller central axis,    the roller and drive transfer member extending between the opposing frame surfaces of the window frame and substantially spanning the distance therebetween to minimize the distance between the opposite shade edges and the respective opposing surfaces of the window frame.    
     
     
         19 . A motor driven shade assembly for use with a flexible shade comprising: 
 an elongated roller supported for rotation about a central axis, the elongated roller adapted for winding receipt of the flexible shade;    a drive transfer member having a central axis, the drive transfer member coupled to an end of the elongated roller to provide for torque transfer from the drive transfer member to the elongated roller;    a drive system having a motor and a drive shaft, said drive shaft having a central axis that is offset from the roller central axis; and    a flexible drive belt engaging an outer surface of the drive transfer member to transfer rotation to the roller from the drive shaft,    the flexible drive belt being made of an acoustically lossy material such that noise transmitted from the drive system to the elongated roller shade is reduced below that which would occur if the motor drive system was directly coupled to the elongated roller.    
     
     
         20 . A motor driven shade system for use with a flexible shade comprising: 
 an elongated roller supported for rotation about a central axis, the elongated roller adapted for winding receipt of the flexible shade;    a drive transfer member having a central axis, the drive transfer member coupled to an end of the elongated roller to provide for torque transfer from the drive transfer member to the elongated roller;    a drive system having a motor extending along a long axis of said drive system, a right angle drive and a drive shaft having a central axis that is offset from the roller central axis; and    a flexible drive belt engaging an outer surface of the drive transfer member to transfer rotation to the roller from the drive shaft,    thereby allowing the long axis of the drive system to be mounted perpendicular to the elongated roller.    
     
     
         21 . The motor driven shade system according to  claim 20  wherein the right angle drive is a worm gear drive.  
     
     
         22 . The motor driven shade system according to  claim 20  wherein said motor driven shade system is adapted for use in a window frame having opposing vertical surfaces and wherein said long axis of said drive system is parallel to one of said opposing vertical surfaces.  
     
     
         23 . A motor driven shade system for use with a flexible shade comprising: 
 an elongated roller supported for rotation about a central axis, said elongated roller adapted for winding receipt of said flexible shade;    a first drive transfer member having a central axis, said first drive transfer member coupled to an end of said elongated roller to provide for torque transfer from said first drive transfer member to said elongated roller, said first drive transfer member having notches arranged peripherally around its circumference;    a drive system having a motor coupled to a drive shaft, said drive shaft having a central axis that is offset from said roller central axis, a second drive transfer member coupled to said drive shaft for rotation therewith, said second drive transfer member having notches arranged peripherally around its circumference, and a drive shaft rotational position detector operatively coupled to provide rotational position information of said drive shaft; and    a flexible drive belt having teeth, said teeth engaging said notches of said first and second drive transfer members to transfer rotation to said roller from said drive shaft, thereby preventing slippage between said first and second drive transfer members and said flexible belt drive such that said drive shaft rotational positional detector can determine the rotational position of said elongated roller.