Window shade positioning apparatus and method

Abstract

An aircraft window shade includes protective transparent window panels, a shade driven by an electric motor, an integral control panel, and support for remote operation. The shade uses dual sprocket drive for positive shade positioning, low wear, and low parts count. The moving shade element remains substantially flat, curving slightly during some phases of positioning. The apparatus replaces a conventional interior window panel and a manual shade with slight change in overall mechanism thickness and weight. Control electronics in the shade can accept a command from a cabin attendant's console to override the local setting and move the shade to a required position, such as fully open for takeoff. The shade supports use of two or more independent shades, each of which can be made of dimming (transparent), diffusing (translucent), or light blocking (opaque) material. The shade is compatible with electrochromic transmittance control technology.

1 . A window shade mechanism, comprising: 
 a first diaphragm incrementally adjustable between an open and a closed position thereof, the first diaphragm comprising a first outer boundary extent and a second outer boundary extent, wherein the first outer boundary extent engages a first guide positioned along a length of the first outer boundary extent;    a first drive sprocket positioned near the first outer boundary extent of the first diaphragm such that the first drive sprocket engages the first outer boundary extent of the first diaphragm; and    a first motor coupled to the first drive socket, wherein the first motor is configured to actuate the first sprocket such that the first diaphragm is incrementally adjustable.    
     
     
         2 . The window shade mechanism as in  claim 1 , wherein the second outer boundary extent of the first diaphragm comprises a second guide positioned along a length of the second outer boundary extent of the first diaphragm.  
     
     
         3 . The window shade mechanism as in  claim 2 , further comprising: 
 a second drive sprocket positioned near the second outer boundary extent of the first diaphragm such that the second drive sprocket is configured to engage the second outer boundary extent of the first diaphragm; and    a coupling between the first motor and the second drive sprocket, wherein the first motor is configured to actuate the second sprocket such that the first diaphragm is incrementally adjustable.    
     
     
         4 . The window shade as in  claim 3 , wherein the first outer boundary extent of the first diaphragm further comprises first receptacles.  
     
     
         5 . The window shade as in  claim 4 , wherein the first drive sprocket further comprises a first plurality of teeth that are configured to engage the first receptacles.  
     
     
         6 . The window shade as in  claim 5 , wherein the second outer boundary of the first diaphragm extent further comprises second receptacles, and wherein the second drive sprocket further comprises a second plurality of teeth that are configured to engage the second receptacles.  
     
     
         7 . The window shade as in  claim 6 , further comprising: 
 a first drive shaft, whereto the first and second drive sprockets are affixed at a lockable angle, whereby engagement between the first plurality of teeth and the first receptacles and engagement between the second plurality of teeth and the second receptacles are substantially synchronizable;    a first drive shaft bearing pair configured to locate and permit rotation of the first drive shaft, wherein the first drive shaft and the first and second drive sprockets affixed thereto establish engagement of the first and second drive sprockets with the first and second receptacles, respectively;    a first motor drive gear affixed to a first motor output shaft; and    a first drive shaft driven gear on the first drive shaft, meshed with the first motor drive gear, whereby rotation of the first motor output shaft is coupled to the first drive shaft.    
     
     
         8 . The window shade as in  claim 7 , further comprising: 
 a first motor encoder, whereby rotation of the first motor is detectable;    a first diaphragm closed end of travel detector, configured such that a signal therefrom indicates that the first diaphragm is in a fully closed position; and    a first diaphragm open end of travel detector, configured such that a signal therefrom indicates that the first diaphragm is in a fully opened position.    
     
     
         9 . The window shade as in  claim 8 , further comprising: 
 a second diaphragm incrementally adjustable between an open and a closed position, the second diaphragm comprising a first and a second outer boundary extent, respectively, wherein the first and second outer boundary extents engage a third and a fourth guide, respectively, positioned along a length of the first and second outer boundary extents, respectively;    a third drive sprocket positioned near the first outer boundary extent of the second diaphragm such that the third drive sprocket engages the first outer boundary extent of the second diaphragm;    a fourth drive sprocket positioned near the second outer boundary extent of the second diaphragm such that the fourth drive sprocket engages the second outer boundary extent of the second diaphragm; and    a second motor coupled to the third and fourth drive sprockets, wherein the second motor is configured to actuate the third and fourth sprockets such that the second diaphragm is incrementally adjustable.    
     
     
         10 . The window shade as in  claim 9 , wherein the first and second outer boundary extents of the second diaphragm further comprise third and fourth receptacles, respectively, and wherein the third and fourth drive sprockets further comprise a third and a fourth plurality of teeth configured to engage the third and fourth receptacles, respectively.  
     
     
         11 . The window shade as in  claim 10 , further comprising: 
 a second drive shaft whereto the third and fourth drive sprockets are affixed at a lockable angle, whereby engagement between the third plurality of teeth and the third receptacles, and between the second plurality of teeth and the second receptacles of the second diaphragm, respectively, are substantially synchronizable;    a second motor drive gear affixed to a second motor output shaft;    a second drive shaft driven gear on the second drive shaft, meshed with the second motor drive gear, whereby rotation of the second motor output shaft is coupled to the second drive shaft;    a second motor encoder, whereby rotation of the second motor is detectable;    a second diaphragm closed end of travel detector, configured such that a signal therefrom indicates that the second diaphragm is in a fully closed position; and    a second diaphragm open end of travel detector, configured such that a signal therefrom indicates that the second diaphragm is in a fully opened position.    
     
     
         12 . The window shade as in  claim 11 , further comprising at least one additional component, wherein the component is selected from the list consisting of: 
 a first window panel, configured to provide a mechanical barrier between the diaphragms and locations inboard of the window shade, further configured to admit substantially all light not blocked by the diaphragms from sources outboard of the window shade to locations inboard of the window shade, further configured to align substantially with a window element of a structure whereto the window shade is attached;    a first window panel attachment fitting, configured to retain the first window panel as an integral element of the window shade apparatus;    a second window panel, configured to provide a mechanical barrier between the movable diaphragms and any materials outboard of the window shade, further configured to admit substantially all light not blocked by the diaphragms from sources outboard of the window shade to locations inboard of the window shade, further configured to align substantially with a window element of a structure whereto the window shade is attached;    a second window panel attachment fitting, configured to retain the second window panel as an integral element of the window shade apparatus;    a diaphragm cover, wherein the diaphragm cover substantially encloses a portion of at least one diaphragm, wherein the diaphragm portion enclosed within the cover is retracted from a diaphragm position between the first and second window panels;    a first motor mount, whereby the first motor is attached to the window shade mechanism;    a second motor mount, whereby the second motor is attached to the window shade mechanism;    a first guide shoe, whereby a distance between the first outer boundary extent of the first diaphragm and the first sprocket at a point of tangency therebetween is maintained; and    a mounting provision, whereby the window shade is attachable to a structure external thereto.    
     
     
         13 . The window shade as in  claim 12 , further comprising a control system, wherein the control system further comprises: 
 a power inlet;    an input power conditioner;    a local control panel;    a local control panel backlight;    a discrete command signal input port;    a remote message transceiver;    a command processor;    an information storage element; and    a first motor drive circuit.    
     
     
         14 . The window shade as in  claim 13 , further comprising a control system, wherein the control system further comprises: 
 a local command interpreter;    a discrete command interpreter;    a remote signal input message parser;    a device address recording provision;    a device address comparator;    a parsed remote command interpreter;    a remote signal reply message formatter;    an authentication code generator;    a first motor speed comparator function;    a first motor speed compensator function;    a soft start function;    a first shade position calculation function;    a first shade position storage function;    a first shade position recall function;    a first shade position comparator function;    an abuse detection function;    an abuse override function;    a local control disable function;    an uncompensatable speed error detection function;    an uncompensatable position error detection function;    an end-to-end count error detection function;    a cumulative run time totalization function;    an error recording function; and    a status report generator function.    
     
     
         15 . The window shade as in  claim 14 , further comprising a manual override, wherein the manual override further comprises: 
 a spool wherein the spool receives drive from an externally applied rotational source;    a lifter, configured to remain at rest, during normal shade operation, outside a range of view through the windows at the closed end of travel of the diaphragms, further configured to translate toward the open end of travel of the diaphragms upon application of tension, further configured to couple tension to the diaphragms, whereby the diaphragms are translated to the open end of travel thereof;    a tension cable, attached to the spool, configured to apply tension to the lifter in a direction tending to translate the lifter toward the open end of travel of the diaphragms, wherein the tension cable is so attached to the lifter as to apply a substantially balanced lifting force thereto; and    a pulley set, configured to direct balanced lifting force to the lifter by distribution and direction of tension applied the tension cable by rotation of the spool.    
     
     
         16 . The window shade as in  claim 15 , wherein the first diaphragm further comprises: 
 a property of opacity sufficient to block substantially all visible light impinging on the diaphragm;    a shape conforming substantially to a rectangular prism, wherein dimensions along a first and a second respectively-orthogonal axis of the shape establish an area comparable to a light admitting area of a window wherebefore the window shade is installed, wherein a dimension of the shape along a third orthogonal axis is no greater in size than one tenth of the smaller of the first and second dimensions, wherein the first and second boundary extents of the diaphragm extend along one of the first and second orthogonal axes of the shape, wherein all edges and corners of the shape have any respective radii of curvature, whereby an extent of planar surface area parallel to the third axis is as little as zero; and    a property of flexibility sufficient to sustain repeated deflection from a first substantially planar surface of motion along a curved guide to a second substantially planar surface of motion.    
     
     
         17 . The window shade as in  claim 16 , wherein the second diaphragm further comprises: 
 A property of light management having at least one attribute selected from the list consisting of reducing light intensity while allowing images to be seen substantially clearly therethrough, and diffusing light while reducing light intensity, whereby substantially no images are readily discernable therethrough;    a shape conforming substantially to a rectangular prism, wherein dimensions along a first and a second respectively-orthogonal axis of the shape establish an area comparable to a light admitting area of a window wherebefore the window shade is installed, wherein a dimension of the shape along a third orthogonal axis is no greater in size than one tenth of the smaller of the first and second dimensions, wherein the first and second boundary extents of the diaphragm extend along one of the first and second orthogonal axes of the shape, wherein all edges and corners of the shape have any respective radii of curvature, whereby an extent of planar surface area parallel to the third axis is as little as zero; and    a property of flexibility sufficient to sustain repeated deflection from a first substantially planar surface of motion along a curved guide to a second substantially planar surface of motion.    
     
     
         18 . A window shade mechanism, comprising: 
 a movable first window shade diaphragm, wherein a first tractionable boundary region of the diaphragm and a second tractionable boundary region of the diaphragm are configured in parallel and at opposed extents of the diaphragm;    a first diaphragm drive sprocket, wherein the first sprocket engages the first tractionable boundary region of the diaphragm;    a second diaphragm drive sprocket, wherein the second sprocket engages the second tractionable boundary region of the diaphragm; and    a first motor coupled to the first and second sprockets.    
     
     
         19 . The window shade mechanism of  claim 18 , further comprising: 
 a first substantially optically transparent panel, positioned substantially parallel to and substantially conterminous with the first diaphragm, having a generally uniform first view surface and having a second view surface generally parallel to the first view surface;    a second substantially optically transparent panel, configured substantially parallel to the first transparent panel, and positioned oppositely from the first transparent panel with respect to the first diaphragm, whereby an enclosed volume is defined wherewithin the first diaphragm is positioned when closed;    
     
     
         20 . The window shade mechanism of  claim 18 , wherein the first tractionable boundary region of the first diaphragm further comprises a first row of drive tooth receptacles, wherein the second tractionable boundary region of the first diaphragm further comprises a second row of drive tooth receptacles substantially parallel to the first row thereof, wherein a traction portion of the first sprocket and a traction portion of the second drive sprocket are substantially identical, and wherein each respective traction portion further comprises: 
 a respective drive sprocket perimeter surface region;    a plurality of sprocket drive teeth projecting from the respective drive sprocket perimeter surface regions, wherein the drive teeth are of such shape and spacing as to engage the respective diaphragm drive tooth receptacles; and    respective first and second sprocket guide shoes, configured to maintain respective first and second spacings, whereby the respective sprocket teeth engage the respective tooth receptacles proximal to a closest point of approach between the respective drive sprockets and the respective guide shoes.    
     
     
         21 . The window shade mechanism of  claim 20 , further comprising: 
 a first panel mounting frame wherewithin the first transparent panel is fitted;    a second panel mounting frame wherewithin the second transparent panel is fitted;    a first side rail connecting the first and second panel mounting frames on a first side;    a second side rail connecting the first and second panel mounting frames on a second side;    a cross rail connecting the first and second panel mounting frames distal to the first shade first and second guide shoes, wherein the cross rail further comprises a connection between the first and second side rails; and    a diaphragm cover enclosing a sheltered volume substantially external to the volume between and including the first and second transparent panels, wherein the sheltered volume is configured to house any portion of the first shade diaphragm not interposed between the first and second transparent panels and not otherwise housed, wherein the cover further comprises a continuation of the sheltered volume configured to house at least in part at least one of the first shade drive motor, the first shade sprockets, the first shade guide shoes, and a first shade drive shaft providing a torque coupling between the first shade sprockets.    
     
     
         22 . The window shade mechanism of  claim 21 , further comprising: 
 a first guide slot associated with the first side rail, wherein the first guide slot is configured to permit the first diaphragm to translate substantially freely in order to follow the median path of the first shade diaphragm;    a second guide slot associated with the second side rail, wherein the second guide slot is configured to permit the first diaphragm to translate substantially freely in order to follow the median path of the first shade diaphragm;    a first boundary surface light trap associated with the cross rail, wherein the light trap is configured to engage a closure boundary surface of the first diaphragm at a closure extent of travel; and    a first drive end gap occupying a space between the first transparent panel and the second transparent panel, comparable in extent to the first boundary surface light trap, proximal to the first shade sprockets, and configured to allow motion of the first diaphragm between the volume generally enclosed between the first and second transparent panels and the volume generally enclosed within the cover.    
     
     
         23 . The window shade mechanism of  claim 22 , wherein the respective first and second side rail first guide slots further comprise: 
 respective pairs of facing surfaces configured with longitudinal extents roughly equal to those of the respective side rails, wherein the respective pairs of facing surfaces are configured with lateral extents sufficient at least to enclose the shade diaphragm drive tooth receptacles, wherein the respective pairs of facing surfaces are each configured with slot profiles between facing surfaces of the slots to accommodate substantially free translation of thickness profiles of the diaphragm and the diaphragm drive tooth receptacles, and wherein the pairs of facing surfaces are joined respectively by a first side rail first slot union surface and a second side rail first slot union surface, wherein each union surface is distal to the centroid of the first shade diaphragm; and    respective first and second light baffles, wherein the respective first and second light baffles substantially block passage of visible light around respective proximal boundary surfaces of a diaphragm fitted within the respective first and second side rail first and second guide slots, and wherein the respective first and second light baffles further substantially block passage of visible light through the associated diaphragm drive tooth receptacles.    
     
     
         24 . The window shade mechanism of  claim 23 , wherein the first shade closure slot further comprises: 
 a pair of closure facing surfaces joined by a closure union surface proximal to a closure extent of travel of the first shade diaphragm, wherein the closure facing surfaces are configured with a longitudinal extent roughly equal to the distance between the first and second side rail first guide slot union surfaces, wherein the closure facing surfaces are configured with a depth sufficient to enclose a shade diaphragm closure boundary surface distal to the drive sprockets, and wherein the facing surfaces are configured with a slot profile between facing surfaces to accommodate substantially free insertion and withdrawal of the closure boundary surface of the first shade diaphragm; and    a third light baffle, wherein the third light baffle substantially blocks passage of visible light around a boundary surface distal to the drive sprockets of a shade diaphragm fully inserted into the first shade closure slot.    
     
     
         25 . The window shade mechanism of  claim 24 , wherein the shade drive end gap further comprises: 
 a pair of drive end gap facing surfaces, wherein the drive end gap facing surfaces are configured with a longitudinal extent roughly equal to the distance between the first and second side rail first guide slot union surfaces, wherein the drive end gap facing surfaces are configured with a slot profile between the drive end gap facing surfaces to accommodate substantially free insertion and withdrawal of the first shade diaphragm; and    a fourth light baffle, wherein the fourth light baffle substantially blocks passage of visible light around a boundary surface of a shade diaphragm fully inserted into the first shade closure slot, and wherein the boundary surface is proximal to the drive end of the housing.    
     
     
         26 . The window shade mechanism of  claim 18 , further comprising: 
 a first drive shaft connecting the first and second drive sprockets, whereby the first and second sprockets rotate at a substantially proportional rim rate;    a first drive shaft bearing pair, configured to locate and permit rotation of the first drive shaft, whereby the first drive shaft and the first and second drive sprockets affixed thereto establish engagement of the first and second drive sprockets with the first and second receptacles, respectively;    a first motor drive gear affixed to a first motor output shaft; and    a first drive shaft driven gear on the first drive shaft, meshed with the first motor drive gear, whereby rotation of the first motor output shaft is coupled to the first drive shaft.    
     
     
         27 . The window shade mechanism of  claim 20 , further comprising: 
 a movable second window shade diaphragm, comprising a specified combination of light transmittance and transparency, comprising substantially parallel first and second shade surfaces, and further comprising a substantially parallel first side surface and second side surface connecting the first and second shade surfaces, wherein the second diaphragm is configured to translate bidirectionally along a median path parallel to a median line substantially equidistant between a first edge joining the first shade surface and the first side surface and a second edge joining the first shade surface and the second side surface of the second diaphragm, wherein the second diaphragm further comprises respective first and second tractionable boundary regions proximal to the respective first and second edges;    a third diaphragm drive sprocket coupled to the second diaphragm, proximal to the first tractionable boundary region thereof;    a fourth diaphragm drive sprocket coupled to the second diaphragm proximal to the second tractionable boundary region thereof;    a second diaphragm drive shaft connecting the third and fourth drive sprockets, whereby the third and fourth sprockets rotate substantially in synchronism;    respective third and fourth guide shoes configured to maintain respective third and fourth spacings between the respective third and fourth drive sprockets and the second diaphragm; and    a second motor, coupled to the second diaphragm drive shaft.    
     
     
         28 . The window shade mechanism of  claim 27 , wherein the respective second shade diaphragm tractionable boundary regions further comprise respective first and second parallel rows of drive tooth receptacles; wherein respective second diaphragm coupling portions of the third and fourth drive sprockets are substantially identical, and wherein each second diaphragm coupling portion further comprises: 
 a drive sprocket perimeter surface region; and    a plurality of radially oriented drive sprocket drive teeth projecting from the second shade drive sprocket perimeter surface region, wherein the drive teeth are of such shape and spacing as to engage the second shade diaphragm drive tooth receptacles.    
     
     
         29 . The window shade mechanism of  claim 21 , wherein the first transparent panel and the first panel mounting frame comprise a single unit, and wherein the second transparent panel and the second panel mounting frame comprise a single unit.  
     
     
         30 . The low profile window shade mechanism of  claim 21 , wherein the first shade first guide shoe and the first side rail comprise a single unit, and wherein the second shade first guide shoe and the second side rail comprise a single unit.