Abstract:
The present invention relates to an architectural window covering having a programmable electric motor. The programmable electric motor is housed within a roller for raising and lowenng the window covering, and includes dual stacked motors and light-transmitting control actuation buttons. In one embodiment an architectural window covering, composing a shade, a roller defining a bore coupled to the shade, and at least two motors axially aligned and electrically coupled in parallel and positioned at least partially in said bore and rotatably coupled to the roller is disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation-in-part of U.S. patent application Ser. No. 12/177,330 (“the &#39;330 application”), which was filed on Jul. 22, 2008, and entitled “PROGRAMMABLE MOTOR FOR WINDOW COVERINGS.” The &#39;330 application is incorporated by reference into the present application in its entirety herein. 
     
    
     FIELD 
       [0002]    The various embodiments of the present invention relate to electrically powered coverings for architectural openings. More specifically, apparatuses, processes, systems and methods are disclosed for providing motorized operation for architectural window coverings. 
       BACKGROUND 
       [0003]    Methods and systems for automatically controlling window coverings have become desirable over the past several decades. Such systems often utilize some type of motor to control the operation of the window coverings. This motor is often implemented within the top of the architectural window covering in a portion referred to as the “head rail”. Because the motor may be implemented within the head rail, depending upon its size, it may cause the head rail to be undesirably large. It may be desirable to minimize the size of the head rail for a variety of reasons. For example, if the head rail is too large it may obstruct the view through the window. 
         [0004]    The size of the motor often depends upon the mechanical torque and/or lifting requirements of the window covering, which in turn, may be dependent upon the size of the window that is being covered and the particular covering being used. In general, larger windows and/or heavier window coverings may require either a large motor that is capable of providing an adequate amount of torque or a smaller motor along with accompanying gearing to provide an adequate amount of torque. Both the larger motor and the smaller motor with accompanying gearing may undesirably consume a great deal of space within the head rail or may generate excessive noise. Thus methods and systems are needed for implementing and controlling motors in window coverings while minimizing their impact on the size of the head rail. 
       SUMMARY 
       [0005]    An architectural window covering having at least one programmable electric motor is disclosed. The at least one programmable electric motors are housed within a tubular motor assembly that, in turn, is housed within a roller structure for raising and lowering said window covering. Further, the at least one motor may be physically linked together by a flexible connector. The at least one electric motor may be partially isolated from the tubular housing by the use of elastomeric damper material 
         [0006]    At least one aspect of the present invention includes an architectural window covering, including a shade; a roller defining a bore coupled to the shade; and at least two motors axially aligned and electrically coupled in parallel and positioned at least partially in said bore and rotatably coupled to the roller. Further, an elongated motor housing may define a cavity; and said at least two motors may be positioned at least partially in said cavity of said motor housing, which may be positioned at least partially in said bore, with the motor housing being rotatable relative to said roller. The at least two motors each have a motor drive shaft and are physically coupled by a flexible connector that connects the motor drive shafts. 
         [0007]    Another aspect of the present invention may include an architectural window covering, including a shade; a roller defining a bore coupled to the shade; at least two motors axially aligned and electrically coupled in parallel and positioned at least partially in said bore and rotatably coupled to the roller; a switch having at least one state and for at least partially controlling the operation of the roller, the switch positioned in said bore; a light indicator positioned adjacent said switch and responsive to the state of said switch; a light pipe member positioned adjacent switch and said light indicator for receiving light emitted therefrom and transmitting the emitted light to be visible by a user, said light pipe member having a portion operably engaging the switch to allow operation thereof by the user. 
         [0008]    Also included as an aspect of the invention is a method of operating an architectural window covering. The method may comprise the use of light pipes to program, alter, reset, and monitor the operation of the architectural window covering. 
         [0009]    In addition to the various examples and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0010]      FIG. 1A  is a perspective view of one type of window covering incorporating at least one aspect of the present invention. 
           [0011]      FIG. 1B  is a cut away view of the head rail in  FIG. 1A  showing the roller assembly and shade. 
           [0012]      FIG. 2A  is a partial view of a roller assembly showing part of the roller positioned around the motor housing assembly. 
           [0013]      FIG. 2B  is an exploded view of the roller, roller ring, and idler ring at the end plate end of the roller assembly. 
           [0014]      FIG. 3A  is an exploded view of the clam-shell housing forming the motor housing assembly. 
           [0015]      FIG. 3B  is an exploded view of the motors, gearbox, and brake assembly. 
           [0016]      FIG. 3C  is section view taken along line  3 C- 3 C in  FIG. 2A . 
           [0017]      FIG. 3D  is an exploded view of the brake assembly. 
           [0018]      FIG. 3E  is a section view between the motors taken along line  3 E- 3 E of  FIG. 3A . 
           [0019]      FIG. 4  is a partial exploded view of the light pipe switch assembly, including the circuit board. 
           [0020]      FIG. 5A  is a section view taken along line  5 A- 5 A of  FIG. 2A  showing a light pipe actuator in the undepressed position. 
           [0021]      FIG. 5B  is a section view similar to  FIG. 5A  showing a light pipe actuator in the depressed position. 
           [0022]      FIG. 6  is schematic view of the tandem motors, circuit board, shade actuator mechanism, position indicator and switches. 
           [0023]      FIG. 7  is an exemplary block diagram of a window covering. 
           [0024]      FIG. 8  is an exemplary velocity characteristic that may be obtained by operating a window covering. 
       
    
    
       [0025]    The use of the same reference numerals in different drawings indicates similar or identical items. 
       DETAILED DESCRIPTION 
       [0026]    A programmable motor arrangement that fits within a head rail of an architectural window covering is disclosed. The programmable motor arrangement may include at least two motors that are tandem stacked within the head rail along with accompanying circuitry. The motors are positioned within a clam-shell motor housing by a plurality of elastomeric dampers that may aid in reducing the transfer of motor vibrations to the housing. The motors may be physically linked using a flexible connector to aid in efficient stacking of the motors. By stacking the motors in a tandem fashion, the amount of radial space that they consume within the head rail may be minimized. Tandem stacking of the motors may also reduce the amount of work required by a single motor to lower or raise a shade and thus may aid in reducing the noise generated in raising and lowering the shade. Additionally, the motors may be electrically connected in parallel and controlled using pulse-width-modulated signals. 
         [0027]    The programmable motor arrangement also may include one or more depressible switches mounted on a circuit board, having a microprocessor and associated control software, that may be positioned in the head rail of the window covering. In some embodiments, these switches may be located proximate to LEDs (light emitting diodes) that also are within the motor housing. The light from the LEDs are visible to the user through light pipes that extend to the exterior of the roller assembly. The light pipes may be coupled physically to the switches and optically coupled to the LEDs. In this manner, the combination of the switches, LEDs, and light pipes may operate jointly to allow the user to enter programming information into the microprocessor accompanying the motor arrangement. The LEDs may also be used to communicate failure of the embodiment and/or motor to the user, as well as other statistical, historical or operational information. 
         [0028]      FIGS. 1A and 1B  show an exemplary architectural window covering assembly  100  according to at least one embodiment. The window covering assembly  100  includes a head rail  102 , a bottom rail  104 , and a shade  106 . (The terms “shade” and “covering” are used generally interchangeably herein.) In various embodiments, the head rail  102  and bottom rail  104  may be formed from aluminum, plastic, or other materials. The exemplary shade  106  shown in  FIGS. 1A and 1B  defines a functional shade and is made of a light fabric. Other shade embodiments include without limitation, pleats, slats, and/or other liftable coverings. Single sheet window coverings such as for example screens are also possible as are projector screens. In various embodiments the shade may be manufactured of a variety of materials, for example, fabric, fiber, plastic, paper, wood, metal, or combinations thereof. It is contemplated that the type of shade and its orientation and mode of actuation are not limited in the implementation of the invention described herein. 
         [0029]    As seen in  FIGS. 1A and 1B , the head rail  102  may include a number of panels. The present embodiment includes a front panel  114 , a top panel  111 , and end caps  112 . The front panel  114  may also define at least one opening or window  115  that may be positioned at or near the edge of the front panel at or near an end cap. The window  115  may be positioned to allow physical and visual access to one or more actuation features, such as buttons, which will be described in greater detail below. 
         [0030]    The panels  111 ,  114  and end caps  112  of the head rail  102  may further define a cavity  116  within the head rail  102 . The front panel  114  may be hinged by pins (not shown), attached at its upper end corners, to the end caps  112 . This may facilitate access to the cavity  116  within the head rail  102  behind the front panel&#39;s front surface  118 . Alternatively, the front panel  114  may be hinged to the bottom member (not shown), or even be fully removable and snapped onto the rest of the head rail  102 . 
         [0031]    In various embodiments, a plurality of lift cords may descend from within the head rail  102 , pass through the cells of the shade  106 , to the bottom rail  104  where they are secured. As such, the weight of the bottom rail  104  and the shade  106  may be supported by the lift cords. It should be noted that, in some embodiments, while lift cords may be tubular strings, alternative exemplary implementation may also be found. The lift cords may be made of any type of material and take many physical forms, such as ribbon shaped pieces of fabric or the like. In some embodiments, the lift cords may be eliminated altogether and the shade  106  may be rolled upon a shaft or roller  122  within the head rail  102 . 
         [0032]      FIG. 1B  shows a cutaway of the head rail  102  allowing a view of a shade/roller assembly  120  positioned within the cavity  116 . In this view, interior surfaces of a back panel  110  and end caps  112  are visible. In the presently depicted embodiment, the shade  106  is attached to a roller  122  at one or more horizontal grooves  124  in the exterior surface  126  of the roller  122 . Other embodiments may attach the shade  106  to the roller  122  other than by use of a groove. The shade/roller assembly  120  is rotatably connected to the head rail  102  by an end plate  128  attached to the interior surface  130  of the end caps  112 . The end plate  128  may be held in place by screws, glue, or by support of a shelf structure on the surface  130  of the end caps  112 . When the roller assembly  120  rotates one direction under the control of the microprocessor, the shade rolls up on the roller assembly to retract the shade. When the roller assembly rotates in the other direction, the shade unrolls from the roller assembly to extend the shade. When not rotating, the roller assembly is kept from rotating by a brake, which may be mechanical or dynamic in nature. The brake assembly is described in detail below. 
         [0033]      FIG. 2A  shows the shade/roller assembly  120  with a partially cut away roller  122 . Positioned inside the roller  122  is a motor tube assembly  132 . The motor tube assembly  132  is a generally cylindrical structure with one end fixedly mounted at or near the end plate  128 , and the opposite end engages a drive ring  134 . The drive ring  134 , as described below further engages both the motor assembly  132  and the roller  122 . 
         [0034]    The drive ring  134  is generally doughnut-shaped and defines a first surface (not observable) positioned toward the center of the motor assembly and a second surface  138  positioned away from the center of the motor tube assembly  132 . The drive ring  134  is attached to the motor tube assembly  132  by engagement of a plurality of projections  170  from the motor tube assembly  132  that extend through the drive ring  134  beyond the second surface  138 . The projections  170  engage the drive ring  134  to form a keyed structure, which may take any number of shapes and structures. The drive ring  134  defines an inner perimeter  140  and an outer perimeter  142 . The outer perimeter  142  is not continuous but is interrupted by at least one notch  144  which extends radially inward from the outer perimeter  142  to create a recess in the outer perimeter  142 . This notch  144  corresponds to and is designed to engage inner radial projections  121  formed by the groove  124  of the roller. The outer perimeter  142  of the drive ring  134  is designed to allow the drive ring  134  to fit into and engage the radial projections  121  on the interior surface  123  of the roller  122 . This engagement structure formed between the roller  122  and the drive ring  134  may allow the roller  122  to be rotated by the movement of the drive ring  134 . 
         [0035]    At the end of the motor tube assembly  132  opposite the drive ring  134  is positioned an idler ring  146 . The idler ring  146  may be slid over the motor tube assembly  132 . The idler ring  146  sits in a channel  148  at or near the end of the motor tube assembly  132 . The idler ring  146 , has a slit therein to allow it to fit over the motor tube assembly  132  and be received in the channel  148 . The slit may allow the idler ring  146  to be opened so that it may more easily fit over or around the diameter of the motor tube assembly  132  or the channel  148 . 
         [0036]    As shown in  FIG. 2B , the idler ring  146  is designed to fit with a roller ring  150  attached to the roller  122 . The roller ring  150  includes a split collar  152  structure with an inner axial edge  154  positioned toward the middle of the length of motor tube assembly  132  and an outer axial edge  156  positioned toward the end plate  128 . Extending radially from the outer edge  156  of the collar  152  is a cap or flange structure  158 . The cap structure  158  further defines an inner surface  160  that contacts the end shoulder  125  of the roller  122 , and an axial outer surface  162  that faces the end plate  128 . Extending radially from the collar  152  are a plurality of fins  164  which are designed to engage the inner surface  123  of the roller  122 . The sections  151 ,  153  in the collar  152  are spaced apart and are designed to accept the radial internal projections  121  formed by the grooves  124  of the roller  122  and aid in securing the roller ring  150  to the roller  122 . When mounted in the roller  122 , the fins  164  engage the internal diameter of the roller  122 , and the radial internal projections  121  are positioned in the gaps between the sections  151 ,  153  of the collar  152 . This engagement structure causes the roller  122  and collar  152  to rotate together. The idler ring  146  fits within the roller ring  150  and is held in place by a raised key  166  in an outer surface of the idler ring  146  that corresponds to a slot  168  in the inner surface of the collar  152 . When in place, the roller ring  150  and idler ring  146  position the motor tube assembly  132  generally in the center of the roller  122  and allow the roller  122  to rotate about the motor assembly  132 . 
         [0037]      FIG. 3A  shows the motor tube assembly  132  exploded to show the structure of the clamshell  180 . With the drive ring  134  removed, the projections  170  that transit through the drive ring  134  are visible. As will be discussed in  FIG. 3B , these projections  170  extend from a shaft tube drive connector which in turn is part of a brake assembly structure  172 . Adjacent the brake assembly  172  is a first tubular motor  200  and a second tubular motor  202 . Extending from the ends of the motors  200 ,  202  are at least one drive shaft. Only one drive shaft  203  is visible in this figure, and it extends from the second motor  202  toward the end plate. A magnet  212  is attached to this drive shaft  203 . The magnet  212  is positioned adjacent a Hall effect sensor (not shown) which aids in controlling the raising and lowering of the shade  106 . 
         [0038]    To keep the motors  200 ,  202  from spinning relative to the clamshell housing  180 , mounting plates  205  may be affixed to the motors  200 ,  202 . In the present embodiment mounting plates  205  are affixed to the ends of the motors  200 ,  202  nearest the drive ring  134 . Other embodiments may position the mounting plates  205  at opposite or adjacent ends. In further embodiments the mounting plates  205  may be affixed at other than the ends of the motors  200 ,  202 . 
         [0039]    The mounting plates  205  have radial tangs  206  that extend through mounting holes  209  in the surface  182  of the clamshell housing  180  to rotationally anchor the motors  200 ,  202  and brake assembly  172 . The tangs  206 , depicted in FIG.  3 B, may terminate at or near the outer surface  182  of the clamshell housing  180 . A damper  207  covers the mounting plates  205 . The damper  207  wraps around the tang  206  to form a collar. The mounting plate  205  dampers  207  of the present embodiment depicted in  FIG. 3B  comprise two semi-circular pieces, however unitary dampers may also be used. There may be unitary dampers  208  positioned at the opposite end of the motors  200 ,  202  from the mount plate  205  dampers  207 . 
         [0040]    The collar  211  structure of the damper  207  surround the tangs  206  at the mounting holes  209 . In operation, the motors  200 ,  202  may be held generally stationary within the clamshell housing  180  by the tangs  206  of the motor plates  205  extending through the mounting holes  209  of the clamshell  180 . The dampers  207  may aid in reducing vibrations generated by the motors  200 ,  202  by forming an buffering layer between the motor plate  205  and the clamshell  180  and by surrounding the tangs  206  with the collars  211 .  FIG. 3C  is a sectional view showing the damper  207  layered between the mounting plate  205  and the clamshell housing  180 . 
         [0041]    The damper material may be an elastomer, for example, without limitation, urethane. In the present embodiment the dampers  207 ,  208  are constructed from Santoprene 55 Shore A. The dampers  207 ,  208  may help to isolate motor vibrations from the clamshell housing  180  and electronics contained therein, and the dampers  207   208  may also help to reduce operational noise. In various embodiments, additional damper material may be used other than at the ends of the motors. 
         [0042]    Returning to a description of the tandem stacked motors,  FIGS. 3B and 3D  show the connectedness of the motors  200 ,  202  and brake assembly  172 . These figures show a motor shaft  201  extending from the first motor  200  and a second motor shaft  203  extending from the second motor  202 . The motor shaft  201  of the first motor  200  may extend through the motor  200  and extend from either end. The shaft  201  extends from the side of the first motor  200  nearest the brake assembly  172 , into a gear box  210 , where the rotational speed of the motor shaft  201  may be translated to a faster or slower rotation of a drive shaft  213 . In the instant case, the shaft  201  engages the gearbox  210  at a certain rpm and torque, and the output shaft  213  from the gearbox  210  has an output of lower rpm and higher torque for operating the shade  106 . In one example, the gearbox has a 102:1 ratio, and the output is about  28  rpm with approximately 1 Nm torque. The drive shaft  213  may be inserted into a gear box shaft connector  214  and fixedly attached by a pin  223  that may traverse the gear box shaft connector  214  and the drive shaft  213  through corresponding aligned holes. The gear box shaft connector  214  further defines two radial protrusions  215 . The radial protrusions are designed to engage the inward pointing tabs  217  of a brake spring  216  that the gear box shaft connector  214  is positioned within. The radial protrusions  215  of the gear box shaft connector  214  also fit within a shaft tube drive connector  219 . The braking spring  216  may be further held in place between a brake mount plate  218  and a brake body cap  221  which is fixedly attached to the brake mount plate  218  by a plurality of screws. The shaft tube drive connector  219  is physically separated from the brake mount plate  218  by a centering washer  222 . An acceptable motor for use in this configuration may include a 12-volt motor, with a 102:1 gear ratio in 3 stages, with an rpm, which may be electronically controlled, of approximately  34 . Such a motor may be available from Buhler Motor. Other motors having similar or different performance characteristics may be acceptable also. 
         [0043]    During operation the motors  200 ,  202  rotate the motor shafts  201 ,  203 . The first motor shaft  201  is coupled to the gear box  210  and causes the drive shaft  213  to be rotated either faster, slower, or the same speed as the motor shaft  201  depending on the gear ratio, which in one embodiment is 1:32. As depicted in  FIG. 3D , the drive shaft  213  in turn causes the gear box shaft connector  214  to rotate which in turn causes the shaft tube drive connector  219  to rotate. Rotation of the shaft tube drive connector  219  causes the drive ring  134 , which is securedly held by the plurality of protrusions  170 , to rotate the roller  122  causing the shade  106  to be raised or lowered. 
         [0044]    Braking may be accomplished by engaging the tabs  217  of the brake spring  216  and the radial protrusions  215  on the gear box shaft connector  214 . When the shaft is not rotating the spring  216  is expanded and pushes against the brake motor housing  218  thus keeping the shade from unfolding. When the motors cause the drive shaft  213  to begin turning, the radial protrusions  215  engage the tabs  217  causing the brake spring  216  to be compressed and releasing it from the brake mount  218  and allowing the gear box shaft  214  to rotate freely. If the roller  122  begins to rotate backward, such as when there is no motor activity, tabs on the shaft tube drive connector  219  engage each other (not shown), causing the brake spring  216  to expand and push again against the interior surface of the brake mount  218  and stop the backward, roller initiated rotation. 
         [0045]    Braking may also be accomplished by using a dynamic brake rather than a spring brake. The dynamic brake may work, as described here and further below, by using a MOSFET H-bridge (and a relay contact shorting the motor). Starting up, the field-effect-transistor (FET) brake may be turned on. The relay may also be turned on causing the short to be removed. Then the motor may be turned on. If the motor turns clockwise the top right FET may be on all the time, and the lower left FET may be pulse width modulated (PWM) appropriately to aid in setting the speed. Speed may be measured by timing between magnet  212  transitions, and the PWM signal may be updated every 20 ms or more or less often. If the speed of the motor is relatively high when the PWM signal approaches zero, then the top FET may be turned off and both lower FETs may be simultaneously pulse width modulated to initiate a “braking PWM” mode. If the speed is too low when the PWM approaches zero, then the system may then be returned to a powered state. Stopping the motor may involve turning on both lower FETs, and turning off the relay which may cause the motor to short. When the power is shut off, the relay may hold the motor. 
         [0046]    The motor shafts  201 ,  203  of the two tubular motors  200 ,  202  may be functionally connected by a tubular flexible connector  220  that fits over the shafts  201 ,  203  that extend from each motor  200 ,  202  toward the other motor. As shown in  FIGS. 3A ,  3 B, and more clearly in  3 E, the tubular flexible connector is sized to fit securely over adjacent motor shaft  201 ,  202  ends of the tandem stacked motors  200 ,  202 . The flexible connector  220  may engage approximately inches of the shaft, with a gap of approximately y inches between the shaft ends. In operation, the flexible connector accommodates the shafts being out of axial alignment, as well as the rotation of the shafts not being identical. This is due to the flexible connector being resistantly deformable in torsion, as well as being bendable along its length. The flexible connector  220  allows the two motors to work in tandem without requiring a rigid coupling. Use of the flexible connector  220  decreases the alignment requirements of tandemly linking the two motors with a rigid connector, and therefore decreases the assembly cost of the housing  132 . In the current embodiment the flexible connector  220  is constructed of neoprene having an inner diameter of 1/16 inch and an outer diameter of 3/16. In various embodiments the flexible connector may be manufactured from other suitable materials and have other sizes. The motor shaft connector  220  may not be cylindrical or tubular in shape, other embodiments may have other structural shapes to aid in connecting the two motor shafts  201 ,  203 . For instance, the connector may have a solid portion positioned between the shafts  201 ,  203 , or the connector may have different geometrical shapes. 
         [0047]    The shade  106  may be raised and lowered by operation of the motors  200 ,  202 . The operation of the motors  200 ,  202  may be controlled through various methods, such as without limitation, infrared, radio frequency, hard wired controls, and buttons  230  positioned at the window  115  in the front panel  114  of the head rail  102 .  FIG. 3A  depicts three buttons  230  located near the end plate  128  of the motor tube assembly  132 . The buttons  230 , (also referred to herein as the user engagement end), define the termini of three light pipes  232 . The light pipes  232  are pivotally attached to a post  234  in the center of the clamshell housing  180 , as described in more detail below. 
         [0048]    Positioned behind the light pipe actuators  232  is a circuit board  306 . The circuit board  306  may have a microprocessor  305  (shown below in  FIG. 7 ) and a plurality of switches  242 . The microprocessor  305 , as described in detail below, may aid in programming, controlling, and monitoring the movement of the motors  200 ,  202  and user initiated input. The microprocessor  305  may receive input from the user in the form of radio frequency, hard wired electrical signals, infrared, or signals generated by manipulation of the light pipe actuators. In addition, the microprocessor may monitor the movement of the motors through inputs from a plurality of sensors positioned near the magnet at the end of motor number two  202 . Thus the microprocessor may turn on, turn off, reverse, accelerate, slow down the motors through integration of a variety of signals. 
         [0049]    The light pipe actuators  232  may be more fully described by reference to  FIGS. 4 ,  5 A and  5 B. The present light pipe actuators  232  each may include a main body  236  having user engagement end  230 , a light receiving end  239  and a switch engagement extension  238 . In the embodiment shown in  FIGS. 4 ,  5 A, and  5 B, the light pipe actuator  232  user engagement end  230  may take the form of a button  230 . A flange  237  extends from the light receiving end  239  to receive through a hole  235 , a pivot pin anchored to the housing and about which the light pipe actuators  232  pivot. When positioned in the clamshell motor housing  180  and engaged with the pivot pin  234 , the light receiving end  239  is adjacent to or contacting the corresponding LED, and the user engagement end  230  is positioned in the window and is accessible by a user. The light receiving end  239  is bent at a right angle to the main body, while the user engagement end  230  is bent at a right angle in the opposite direction. The switch is spring loaded to bias the light pipe actuator  232  outwardly and against a retaining shoulder of the housing (See  FIG. 5A ). 
         [0050]    Light emitted from the LED  240  enters the light receiving end  239  of the light pipe  232 . The light then travels the length of the main body  236  and is emitted from the light pipe at the user engagement end  230 . The smooth and rounded nature of the main body  236  of the light pipes  232  aids in transmitting the light from the LED to the button. In addition the selected material for light pipe  232  manufacture may also aid in light transmission. For example, light pipes  232  may be made out of a rigid translucent material such as plastic or glass. In the current embodiment, the light pipe  232  is constructed from Lexan. 
         [0051]    As described above, the light pipes  232  may have at least two functions. First, the light pipes  232  may transmit light from the LEDs  240  positioned at the opposite end of the first portion  236  of the light pipes  232  to the button. Second, the light pipes  232  may aid in the manual control of the motor tube assembly  132  through the actuation of at least one switch  242  positioned at or near the switch engagement portion  238  of the light pipe  232 . 
         [0052]    Manual control of the motor tube assembly  132  is depicted in  FIGS. 5A and 5B . The one or more switches  242  and the one or more LEDs  240  in combination with the one or more light pipes actuators  232  may communicate various operational and/or programming options to the user, and allow the user to communicate commands to the microprocessor  305 . For example, the one or more light pipes  232  may couple light from the one or more LEDs  240  to the user viewing the front panel  114 . Additionally, the one or more light pipes  232  may be physically pressed by the user, and the one or more light pipes  232  in turn, may couple this to the to the one or more switches  242 . Thus, the one or more light pipes  232  may provide mechanical coupling of the one or more switches  242  through the motor housing assembly  132  and the headrail  103  to the user. 
         [0053]    In some embodiments, the user may program predetermined thresholds (i.e. limits) using the one or more light pipe actuators  232 . These thresholds may include how far up or down the shade  106  may be within the window. Also, the one or more LEDs  240  may be used to echo the programming selections and/or stored threshold values back to the user during programming. In some embodiments, these thresholds may be changed dynamically by the user operating the shade  100 . 
         [0054]    The buttons  230  of the current embodiment may emit different colors. For example, one button  230  may emit red light and be used in setting the upper limit of the shade, while the green button may be used to set the lower shade limit. A yellow button may be used to clear any limits and/or re-establish factory settings. In various other embodiments the colors and functions associated with specific buttons may vary 
         [0055]    One exemplary implementation of the switches  242 , the LEDs  240 , and the light pipes actuators  232 , as shown in  FIGS. 5A and 5B , will now be discussed. The pivot extension  237  of the light pipe  232  may define a post hole  235  whereby the light pipe  232  may pivot about this hole  235  when the light pipe  232  is pivotally fixed through the hole  235 . Further down the light pipe  232  the switch engagement extension  238  may extend off and rest on the switch  242 . The light pipe  232  may protrude through the clamshell housing  180  and the front surface  118  of the head rail  102  allowing the user to depress the user engagement end  230  to actuate the switch  242 . By depressing the light pipe activator  232  at the user engagement end  230 , the light pipe  232  may rotate about the pivot post  234  and cause the switch engagement extension  238  to push on the switch  242 . Activating the switch changes its state and provides instructions to the microprocessor. 
         [0056]    Thus, after installation of the architectural window covering, a user may initiate operation by depressing a pre-determined combination of light pipe actuators. This may in turn initiate a pre-programmed series of set-up modes to allow the user to set maximum and minimum shade positions, speed of shade movement and other desirable parameters. The microprocessor may integrate the signals received from either user input through the light pipe actuators, radio frequency signals, or a remote keypad. The microprocessor then relays the signals to the motors to speed up, slow down, stop or reverse, while monitoring the operation of the motors through signals generated by the Hall effect sensor and encoder. 
         [0057]    During operation, the motors  200 ,  202  may be electrically coupled together in a parallel fashion. In some embodiments, the motors  200 ,  202  may be controlled using a pulse-width-modulated (PWM) signal. By varying the duty cycle of the PWM signal the average voltage delivered to the motors  200 ,  202  may be controlled to match the operating conditions of the architectural window covering  100 . For example, a low average voltage for the PWM signal (e.g., duty cycle 20%) may correspond to moving the architectural window covering  100  relatively slowly while a high average voltage for the PWM signal (e.g., duty cycle 80%) may correspond to moving the window covering relatively quickly. 
         [0058]    By implementing two or more tandem stacked motors, the head rail  102  may be kept compact while providing additional torque to increase the mechanical strength provided to operate the architectural window covering assembly  100 . For example, if the architectural window covering assembly  100  is fashioned about an unusually long window, so that the weight of the architectural window covering may be greater than normal, one or more additional tandem stacked motors may be added to the head rail  102  as necessary to handle the additional mechanical strength requirements. 
         [0059]    In addition, the use of multiple tandem motors may allow certain embodiments to generate sufficient torque to raise or lower the shade  106  (or other covering for an architectural opening) while simultaneously reducing gearbox ratios. In a standard drive system for a shade, a single motor requires a relatively high rotational speed given the gearing of the motor. This, in turn, often leads to the motor producing an audible noise during operation. By contrast, certain embodiments may operate the motors  200 ,  202  at a lower speed since the dual-motor arrangement may generate torque equivalent to a single-motor system operating at a higher speed. Accordingly, the operational noise of the present embodiment may be reduced and, in some cases, relatively inaudible (depending on placement of the embodiment and distance to a listener). 
         [0060]    As illustrated with the schematic representation in  FIG. 6 , a drive rail encoder  250  may be coupled to a motor shaft  203 . The encoder  250  may include multiple regions (depicted as alternating black and white pie shaped regions on the circular encoder  250 ) angularly positioned about a motor shaft  203 . As the motor shaft  203  rotates, regions on the encoder  250  pass by one or more angular sensors  252  that may be read by a control circuit  254 . (The control circuit  254  is described in more detail below with regard to  FIG. 7 ). During operation, the encoder  250  may indicate angular movement of the motor shaft  203 , such as the angular position, velocity, and/or acceleration of the motor shaft  203  to name but a few. In some embodiments, a microprocessor  305  (described more fully below) may use signals generated by the sensors  252  reading the movements of the encoder  250  to monitor and regulate the movement of the motors  200 ,  202 . For example, the microprocessor  305  may monitor movement of the motors  200 ,  202  to track the position of the shade  106  in the window. If the microprocessor detects that the shade  106  is traveling too fast or beyond its programmed limits, the microprocessor  305  may send a signal to the brake to slow or stop the motors  200 ,  202 . 
         [0061]    The control circuitry  254  may convert angular movement reported by the one or more sensors  252  into electrical impulses in analog or digital form for further processing. One or more switches  242  may be coupled to the control circuitry  254 . The switches  242  may be capable of receiving user input, for example, by acting as a depressible switch that is electrically coupled to the control circuitry  254 . The control circuit  254  also may couple to one or more LEDs  240  that emanate light. In some embodiments, the LEDs  240  may communicate the operational status of the window covering  100  to the user as described above. In other embodiments, the LEDs  240  may communicate user programming settings effectuated through the one or more switches  242 . 
         [0062]      FIG. 7  represents a block diagram of the widow covering assembly  100  illustrating an exemplary configuration for the control circuitry  254 . As shown, the control circuit  254  may include a microprocessor  305  coupled to a bridge circuit  310 . In some embodiments, the bridge  310  may include one or more field-effect transistors (FETs) that provide power to the motors  200 ,  202 . In other embodiments, the bridge  310  includes insulated gate bipolar transistors (IGBTs) that combine the advantages of a FET with the advantages of a bipolar transistor when providing power to the motors  200 ,  202 . During operation, the microprocessor may monitor angular measurements of the motors  200 ,  202  from the combination of the sensor  252  and the encoder  250 . 
         [0063]    Angular measurement may also be obtained from the magnet  212  and Hall effect sensor  252 , insofar as the sensor  252  may detect every time a certain magnetic polarity is adjacent the sensor. Further, the sensor  252  may measure the period of each such transition. Based on these angular measurements and the periods of transition, the microprocessor  305  may determine the distance traveled and velocity of the shade  106 . Additionally, based upon measurements from the combination of the sensor  252 , the encoder  250 , and the up and down thresholds of the architectural window covering  100  set by the user, the microprocessor  305  may determine the position of the architectural window covering  100  with respect to its upper and lower extension limits. The microprocessor  305  may generate one or more error signals based upon the difference between the angular measurements of the motors  200 ,  202  or the periods of transitions sensed by the sensor and the desired values programmed in the microprocessor  305  (e.g, exert positional control). In this manner, the combination of the microprocessor  305 , the motors  200 ,  202 , and the encoder  250 /magnet  212  may form an adaptive feedback and control loop to control overall operation of the motors  200 ,  202  using the output of the magnet  212  or encoder  250 , depending on the embodiment in question. 
         [0064]    In particular,  FIG. 8 , with reference to  FIG. 7 , displays an exemplary operating curve  350  when raising or lowering a shade  106  for certain embodiments. The operating curve  350  is shown on a graph having velocity as the Y-axis and distance as the X-axis. Here, both velocity and distance are expressed with respect to the shade  106  (e.g., the velocity and distance traveled of the shade). Initially, as the motors  200 ,  202  extend or raise the shade in the manner described above, the shade&#39;s velocity varies with the distance traveled (e.g., the shade accelerates). At a first equilibrium point  337 , the velocity of the shade is held constant as the shade continues to travel. At a second equilibrium point  339 , the embodiment senses via the sensor  252  that the shade is nearing an endpoint of its travel. Accordingly, the motors decelerate the shade such that its velocity returns from a constant value to zero across a certain distance. Thus, at the end point  333 , the shade&#39;s travel is complete and its velocity is zero. The first and second equilibrium points  337 ,  339  thus define the beginning and end of the constant velocity portion of the operating curve  350 , which is the section where the shade&#39;s velocity is in equilibrium. 
         [0065]    In some embodiments, the window covering&#39;s velocity between the starting point  331  and the ending point  333  may be non-uniform. For example, in the exemplary operating curve  350 , the architectural window covering  100  may slightly accelerate or slightly decelerate during the otherwise constant velocity segment of the curve  350  to maintain an overall constant velocity and, for example, to correct for error or jitter in the travel of the shade. 
         [0066]    In some embodiments, the acceleration and deceleration portions of the operating curve  350  may be accomplished in whole, or in part, by one of the motors  200 ,  202 . 
         [0067]    Between the equilibrium points  337 ,  339 , the motors  200 ,  202  may operate at a predetermined velocity  335 . The predetermined velocity  335  may be preprogrammed during manufacture of the architectural window covering  100 , or alternatively, may be programmed by the user after installation. 
         [0068]    It should be noted that various operating curves may be employed. For example, the operating curve may be exponentially increasing instead of linearly increasing between points  331  and  337 . Furthermore, in some embodiments, the architectural window covering  100  may include a tensioning sensor to determine when the architectural window covering  100  reaches the top or the bottom of the window opening and the operating curve may be modified accordingly. For example, the operating curve may be saw tooth shaped so that the architectural window covering may descend at a constant velocity for a short distance and then stop to determine the tension in the cords  320  and adjust operation accordingly. 
         [0069]    During non-operation, the architectural window covering  100  may be in a powered off state, for example, because the desired window position has been achieved and no further adjustments in position are desired by the user. When the user desires to move the architectural window covering  100  after being powered down, the control circuit  254  may power itself up and determine the position of the architectural window covering prior to power down. Then, upon power up, the microprocessor  305  may use this last known position of the architectural window covering to move the architectural window covering  100  to the user&#39;s new desired position according to the operating curve  350  and/or last known position of the covering  100 . For example, the user may set the architectural window covering  100  to be midway between the first and second intermediate points, at a third intermediate point  341 , and then leave the architectural window covering  100  in that position for an extended period of time. After a predetermined period of time (which may be programmed by the user into the microprocessor  305 ) the control circuit  254  may enter a low power mode or power off completely to conserve power, and while doing so, may save the position of the architectural window covering  100  prior to power down. In this example, the last position prior to power off is the intermediate point  341 . When the user later wants to readjust the position of the architectural window covering  100 , the control circuit  254  may power back up, determine that the last position of the architectural window covering  100  was the third intermediate point  341 , and then move the architectural window covering according to the operating curve starting at the third intermediate point  341 . 
         [0070]    Referring again to  FIG. 7 , the control circuit also may include one or more optional (as indicated by the dashed boxes) interface and protection circuits  315 A-B. The protection circuits  315 A-B may filter the microprocessor  305  and the other circuitry within the control circuit  254  from external electromagnetic interference (EMI) and electrostatic discharge (ESD). In addition, the protection circuits  315 A-B also may filter out internal EMI/ESD from signals coming from the control circuit  254  to ensure that the control circuit  254  complies with FCC requirements. 
         [0071]    The protection and interface circuit  315 A may include one or more manual user inputs or switches to control the position of the architectural window covering  100  in the window. In some embodiments, this may include single-pole-single-throw type switches that are located at a geographically different location than the architectural window covering  100  or the control circuit  254 . In other embodiments, this may include a single-pole-double-throw type switch that is located at a geographically different location than the architectural window covering  100  or the control circuit  254 . The user may program the control circuit  254  using the protection and interface circuit  315 A by actuating the switch to the up, down, and/or neutral positions. 
         [0072]    The protection and interface circuit  315 B may include a bidirectional data interface such as an RQ™type interface standard from Electronic Solutions, Inc. of Lafayette, Colo. The RQ™type interface is a six conductor bidirectional full-duplex data interface. Alternative embodiments may use the unidirectional RP type data communication protocol that provides simplex communication. In still other embodiments, the protection and interface circuit  315 B may include a bidirectional data protocol or communication interface, such as the Z-wave™ interface from Zensys. Implementing Z-Wave™ allows low power consumption, 2-way RF, mesh networking technology and battery-to-battery support. During operation, Z-Wave™ mesh networking technology routes 2-way command signals from one Z-Wave™ device to another around obstacles or radio dead spots that might occur. Additional interface types may include CAN, LON, and Zigbee to name but a few. 
         [0073]    Regardless of the type of bidirectional data interface used, the interface may allow the microprocessor  305  to be queried as to the present status of the architectural window covering  100 . For example, in some embodiments the architectural window covering  100  is configured with a graphic on it so as to display a message or logo. The message or logo may be displayed as the architectural window covering  100  rotates its shades back and forth, which may be a function of the position of the drive shaft  203 . Thus, the interface may be used to remotely control the message or logo displayed on the shades of the architectural window covering  100  by allowing the user to query the position of the roller  122 . 
         [0074]    In addition, a plurality of window coverings may be linked together via an interface and user commands may be echoed between window coverings within the plurality. For example, all of the window coverings on the East side of a building may be linked together via the interface and a user standing at one end of the building and desiring to operate all the window coverings in unison may provide the desired command to the architectural window covering the user happens to be standing by and have the desired command echoed to all window coverings on that same interface. 
         [0075]    The architectural window covering  100  may include the power circuitry  270 . As shown in  FIG. 7 , the power circuitry  270  may provide power to the bridge  310 , the protection circuits  315 A-B, the microcontroller  305 , the one or more switches  242 , and or the one or more angular sensors  250 . The power circuitry  270  may receive a 12-24 volt DC input power and provide various output voltage levels. For example, the interface and protection circuit  315 B may operate at 10 volts while the microcontroller  305  may operate at 5 volts. The power circuitry  270  is capable of supplying power at both these levels as well as many others. In some embodiments, the protection circuit  315 A may receive its power via the microcontroller  305 . In alternative embodiments, the input power may range from 12 to 40 volts DC. 
         [0076]    The power circuitry  270  may provide a power fail detection line to the microprocessor  305 . In the event that the power circuitry  270  detects that the main power supplied to the power circuitry  270  has been turned off, then it may warn the microcontroller  305  this has occurred via the power fail detection line shown. The power circuitry  270  also may include the ability to implement an efficient power down scheme. In order to give the power circuitry  270  sufficient hold-up time for the microcontroller to execute a power down sequence, the power circuitry  270  may include a capacitor that stores enough charge to power the microcontroller while it executes the power down scheme. In some embodiments, this scheme includes determining that power is going away, for example, by the microcontroller determining that the power main has been shut off. As a result, the microprocessor  305  may stop the two or more motors  200 ,  202 , monitor the deceleration of the encoder  250 , and save the state of the encoder  250  for use when the architectural window covering is powered back on. 
         [0077]    The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent once the above disclosure is fully appreciated. For example, the programmable motor arrangement may find application in a variety of settings outside the context of architectural window coverings such as in garage door openers or with retractable projection screens. The claims should be interpreted to include any and all such variations and modifications. In addition, the above description has broad application, and the discussion of any embodiment is meant only to be exemplary, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these embodiments.