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BACKGROUND OF THE DISCLOSURE 
       [0001]    1. Field of the Disclosure 
         [0002]    The subject disclosure relates to a garage door assembly, and more particularly to an improved position reading assembly for determining and controlling position of a garage door of the assembly. 
         [0003]    2. Background of the Related Art 
         [0004]    Garage door assemblies are used to cover openings of all sizes. Use of garage door assemblies has been widely used and well understood in the art. Some examples are illustrated in U.S. Pat. No. 6,806,672 to Fitzgibbon et al. (&#39;672 patent), U.S. Patent Application 2005/0140323 to Fitzgibbon et al. (2005/0140323 application), U.S. Pat. No. 6,878,927 to Smith et al. (&#39;927 patent), U.S. Pat. No. 6,956,199 to Smith et al. (&#39;199 patent), and U.S. Patent Application 2002/0175276 to Smith et al. (2002/0175276 application), each of which is incorporated herein by reference. 
         [0005]    The &#39;672 patent and the 2005/0140323 application disclose movable barrier operators with a microprocessor 300 that provides the signals which start the motor 116, control the direction of rotation, and the speed of rotation. (See &#39;672 patent column 9, ll. 38-41; 2005/0140323 application paragraph 0060). The &#39;672 patent and 2005/0140323 application discloses an RPM sensor module in the motor 118. (See &#39;672 patent column 4, ll. 11-33; column 10, ll. 9-10, 2005/0140323 application paragraph 0017). The &#39;672 patent discloses a subroutine that checks the position of the door. (See column 20, ll. 48-60, 220/0140323 paragraph 0094). 
         [0006]    The &#39;927 patent, the &#39;199 patent and the 2002/0175276 application also disclose movable barrier operators with an absolute position detector that provides a unique value for each position along the path of travel. The absolute position detector uses two binary serial streams and one clock stream. After the first five cycles of the clock stream, the binary serial streams can be decoded by a microprocessor to produce an absolute position indication. The absolute position is calculated given the bit streams and the clock pulse. (See &#39;927 patent and &#39;199 patent column 2, ll. 15-column 3, ll. 30; 2002/0175275 application paragraphs 34-47). 
       SUMMARY OF THE INVENTION 
       [0007]    There are problems associated with prior art garage door assemblies such as undesirable complexity, high cost, cumbersome operation and poor reliability. A need exists for a reliable, cost-effective garage door assembly that constantly monitors the position of the door and can recover properly in the event of a power failure. 
         [0008]    The present disclosure is directed to a garage door assembly having three position readers within the same unit. The three position readers are used to ascertain measurements that virtually divide the door into eight sections to determine the position of the door. Preferably, the garage door assembly further includes an additional reader to determine a location of the door within each of the eight virtual sections. 
         [0009]    Another embodiment of the present disclosure includes a garage door assembly including a door for enclosing an opening, and a mechanism for selectively deploying the door in a closed position to cover the opening, and an open position with the door stored leaving the opening uncovered. A position reading assembly monitors a position of the door with respect to the opening. The position reading assembly includes a controller and three switches in communication with the controller. The switches are positioned such that movement of the door actuates the three switches and, in turn, the controller divides the door into eight virtual zones between the closed and open positions. 
         [0010]    The garage door assembly may further include an intra-section reader for monitoring position of the door within each zone. In one embodiment, the door is flexible and wraps around a reel in the closed position. The garage door assembly may also include a gearing mechanism assembly for wrapping and unwrapping the door, a tracking wheel coupled to the gearing mechanism such that movement of the door from the fully open to the fully closed position results in a single rotation of the tracking wheel and sensor activating means mounted on the tracking wheel for activating the three switches. The sensor activating means may be a flag, a varying diameter, markings, a magnet, an RFID component, and combinations thereof. 
         [0011]    The present technology is also directed to a method for operating a garage door including the steps of providing three switches on the garage door that operate to divide the garage door into eight virtual zones. Upon restart after power loss, the three switches are polled to determine which of the eight virtual zones the garage door is located in. If the garage door is oriented such that the garage door is almost or fully open based upon the polling, a position of the garage door is reset by moving the garage door downward until the garage door enters the adjacent virtual zone. The method may also perform the step of, if the garage door is at least one virtual zone away from being fully open based upon the polling, resetting the position of the garage door to fully open by moving the garage door upward. Still further, the method may also determine upper and lower travel limits of the garage door by polling the three switches and/or providing an intra-zone reader to track a position of the garage door within each zone. 
         [0012]    It should be appreciated that the present invention can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device, a method for applications now known and later developed. These and other unique features of the system disclosed herein will become more readily apparent from the following description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    So that those having ordinary skill in the art to which the disclosed system appertains will more readily understand how to make and use the same, reference may be had to the drawings. 
           [0014]      FIG. 1  illustrates a perspective view of a garage door assembly constructed in accordance with a preferred embodiment of the subject disclosure with the housing of the position reading assembly partially cut away. 
           [0015]      FIG. 2  illustrates a perspective view of the position reading assembly of  FIG. 1 . 
           [0016]      FIG. 3  illustrates an plan view of another position reading assembly in accordance with the subject disclosure. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0017]    The present disclosure overcomes many of the prior art problems associated with garage door openers. The advantages, and other features of the system disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements. 
         [0018]    All relative descriptions herein such as left, right, up, and down are with reference to the Figures, and not meant in a limiting sense. Unless otherwise specified, the illustrated embodiments can be understood as providing exemplary features of varying detail of certain embodiments, and therefore, unless otherwise specified, features, components, modules, elements, and/or aspects of the illustrations can be otherwise combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged without materially departing from the disclosed systems or methods. Additionally, the shapes and sizes of components are also exemplary and unless otherwise specified, can be altered without materially affecting or limiting the disclosed technology. 
         [0019]    Now referring to  FIG. 1 , a perspective view of a garage door assembly constructed in accordance with a preferred embodiment of the subject disclosure is illustrated and referred to generally by the reference numeral  100 . The garage door assembly  100  is used to selectively cover an opening in a building  10 . Normally, the garage door assembly  100  is mounted at the top of the opening and descends but other configurations would also be able to successfully employ the subject technology. 
         [0020]    The garage door assembly  100  includes a door  102  that winds onto a reel assembly  104 . The reel assembly  104  is mounted to the wall by a bracket  106 . A position reading assembly  108  couples to the reel assembly  104  and is powered by an outlet  110 . The position reading assembly  108  includes a motor (not explicitly shown) for winding and unwinding the door  102  from the reel assembly  104 . A manual switch  112  hangs from the position reading assembly  108  to manually operate the garage door assembly  100 . The garage door assembly  100  may also be operated by a remote switch as is well known in the art. 
         [0021]    The position reading assembly  108  includes components (best seen in  FIG. 2 ) contained within a housing  114  to prevent dust and like contaminants from interfering with proper operation. In  FIG. 1 , the housing  114  of the position reading assembly  108  is shown partially cut away. 
         [0022]    Referring to  FIG. 2 , a perspective view of the components of the position reading assembly  108  is illustrated. The position reading assembly  108  virtually divides the door  102  into eight sections. The position reading assembly  108  has three sensors  116   a - c . Although sensor  116   c  is not shown explicitly, an approximate location is noted on  FIG. 2 . Each sensor  116   a - c  has two states, ON and OFF. Thus, eight different combinations of sensor states are possible, one for each virtual section. In one embodiment, the door  102  is 400 cm. and each virtual door section is 50 cm. 
         [0023]    Each sensor  116   a - c  is fixed in place on a frame  118  that surrounds a gearing assembly  120 . The gearing assembly  120  includes a rotational tracking wheel  122  that interacts with the sensors  116   a - c . The gearing assembly  120  is coupled to the reel assembly  104  so that the tracking wheel  122  completes approximately one rotation when the door  102  moves from fully open to fully closed. In one embodiment, a central hub  124  couples to the motor or rotating rod (not explicitly shown) supporting the door  102 . As the central hub  124  rotates, a plurality of gears in the gearing assembly  120  translate the motion into the required single rotation of the tracking wheel  122 . 
         [0024]    In one embodiment, the sensors  116   a ,  116   b  are mechanical switches, e.g., switches with extending arms that move between an ON and OFF position to generate corresponding electrical signals. The sensor  116   c  is a photo interrupter that changes state when a beam of energy is blocked. The sensors  116   a - c  may be normally ON or OFF as desired. In the embodiment of  FIG. 2 , the sensors  116   a - c  are separated by 90 degrees about the periphery of the tracking wheel  122 . 
         [0025]    The tracking wheel  122  has equal and opposing portions  126   a ,  126   b  of two different diameters to interact with the sensors  116   a ,  116   b . The tracking wheel  122  has a relatively larger diameter at portion  126   a . A series of four flags  128  (only one can be seen) are equally spaced and peripherally mounted to interact with the sensor  116   c . Each flag  128  spans 45 degrees with 45 degree spaces therebetween. 
         [0026]    In the orientation of  FIG. 2 , it can be seen that sensors  116   a ,  116   b  would be activated (e.g., an ON state if normally OFF) by the thicker diameter portion  126   a . Although out of view, the sensor  116   c  would also have a flag  128  interacting therewith to be activated (e.g., an ON state if normally OFF). As the door  102  moves through the virtual sections, the tracking wheel  122  rotates and the state of the sensors  116   a - c  changes. 
         [0027]    For example, see Table 1 below that illustrates the various sensor states as the door  102  moves on and off the reel assembly  104  and, in turn, the tracking wheel  122  rotates. Table 1 is based on the orientation illustrated in  FIG. 2  being a fully open position but the subject technology is not limited to such. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Virtual Door 
                 Amount of  
                   
                   
                   
               
               
                 Section Descending 
                 Clockwise 
                 Sensor 
                 Sensor 
                 Sensor 
               
               
                 into Opening 
                 Rotation 
                 116a 
                 116b 
                 116c 
               
               
                   
               
             
             
               
                 none 
                 Fully open, no 
                 1 
                 1 
                 1 
               
               
                   
                 rotation from FIG. 2 
               
               
                 1 of 8 
                   1-45 degrees 
                 1 
                 1 
                 1 
               
               
                 1 and 2 of 8 
                  46-90 degrees 
                 1 
                 1 
                 0 
               
               
                 1-3 of 8 
                  91-135 degrees 
                 0 
                 1 
                 1 
               
               
                 1-4 of 8 
                 136-180 degreees 
                 0 
                 1 
                 0 
               
               
                 1-5 of 8 
                 181-225 degrees 
                 0 
                 0 
                 1 
               
               
                 1-6 of 8 
                 226-270 degrees 
                 0 
                 0 
                 0 
               
               
                 1-7 of 8 
                 271-315 degrees 
                 1 
                 0 
                 1 
               
               
                 1-8 of 8 
                 316-360 degrees 
                 1 
                 0 
                 0 
               
               
                 8 of 8 fully 
                 Fully Closed - 
                 1 
                 0 
                 0 
               
               
                 deployed 
                 360 degrees 
               
               
                   
               
             
          
         
       
     
         [0028]    As can be seen from Table 1, each virtual section of the door  102  corresponds to 45 degrees of rotational travel of the tracking wheel  122 . The position reading assembly  108  and/or control electronics associated therewith can be programmed to recognize upper and lower travel limits upon certain changes in sensor values. For example, if sensors  116   a - c  switch from respective states ON, OFF, OFF to ON, ON, ON, then the door has been fully closed. Similarly, if sensors  116   a - c  switch from respective states ON, ON, ON to ON, OFF, OFF, then the door has been fully opened. As the tracking wheel  122  normally moves back and forth, these conditions would only occur at the limits of travel. Alternatively, separate sensors (not shown) may be coupled to the door  102  in order to determine the fully open and closed positions. 
         [0029]    Still referring to  FIG. 2 , the position reading assembly  108  also includes an intra-section position reader  130 . Thus, when the door  102  and, in turn, the tracking wheel  122  pass from one virtual section to another, the intra-section position reader  130  begins tracking the intra-section movement. Preferably, the resolution of the intra-section position reader  130  is five hundred finer sections within each fifty centimeter virtual section. In one embodiment, the intra-section position reader  130  includes alternating lines and spaces on the periphery of the tracking wheel  122  that are read by an encoder assembly. Alternatively, the motor of the position reading assembly  108  may be encoded to track movement thereof to provide the intra-section readings. 
         [0030]    The garage door assembly  100  can recover from a lost power situation. For example, upon power up, the garage door assembly  100  may be programmed to move to the up limit position, e.g., fully open. When power is restored to the garage door assembly  100 , the position reading assembly  108  can poll the sensors  116   a - c  to determine roughly where the virtual sections of the door  102  are. 
         [0031]    If the door  102  is positioned such that the door  102  is within a virtual section from being fully open (e.g., the sensors  116   a - c  reading ON, ON, ON), the position reading assembly  108  can send the door  102  downward until the reading of sensor  116   c  changes to OFF. At this point, the position reading assembly  108  can recognize that the door  102  is approximately one virtual section from fully open and proceed to that position. In one embodiment, the reversal of door direction would occur, as the sensor  116   c  changes back to an ON state, the intra-section position reader  130  would be reset to properly track door movement to the open position. In another position, the door is in a different section, the position reading assembly  108  recognized this and directs movement upward so that the last virtual section is reeled in with the process noted above starting. In another embodiment, upon finding the bottom of the first virtual section, the intra-section position reader  130  is used to set the fully open position. 
         [0032]      FIG. 3  illustrates an plan view of another position reading assembly  200  in accordance with the subject disclosure. The orientation of  FIG. 3  is such that the door has just entered the first virtual section, i.e., the door has just begun to cover the building opening. As will be appreciated by those of ordinary skill in the pertinent art, the position reading assembly  200  utilizes similar principles to the position reading assembly  100  described above. Accordingly, like reference numerals preceded by the numeral “2” instead of the numeral “1”, are used to indicate like elements. The following discussion is directed to the differences. Some primary differences of the position reading assembly  200  in comparison to the position reading assembly  100  is the use of three photo interrupter sensors  216   a - c  rearranged to interact with five flags  240 ,  242   a - d  and a different intra-section position reader assembly  230 . 
         [0033]    The sensors  216   a - c  and intra-section position reader  230  are mounted on a sensor plate  244 . Sensors  216   a ,  216   c  remain separated by 90 degrees but sensor  216   b  has been repackaged adjacent to sensor  216   a  and radially inward with respect to the tracking wheel  222 . The flags  240 ,  242   a - d  depend from the tracking wheel  222  to interact with the sensors  216   a - c , wherein each sensor  216   a - c  is a photo-interrupter. The large flag  240  is approximately a 180 degree arc that will pass through sensors  216   a ,  216   c  whereas the four smaller flags  242   a - d  are four equally spaced, approximately 45 degree arcs that will pass through sensor  216   b . An exemplary chart illustrating the sensor  216   a - c  reading is shown below in Table 2. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Virtual Door 
                 Amount of 
                   
                   
                   
               
               
                 Section Descending 
                 Clockwise 
                 Sensor 
                 Sensor  
                 Sensor 
               
               
                 into Opening 
                 Rotation 
                 216a 
                 216b 
                 216c 
               
               
                   
               
             
             
               
                 none 
                 Fully open 
                 1 
                 1 
                 0 
               
               
                   
                 as shown in FIG. 3 
               
               
                 1 of 8 
                   1-45 degrees 
                 1 
                 1 
                 0 
               
               
                 1 and 2 of 8 
                  46-90 degrees 
                 1 
                 0 
                 1 
               
               
                 1-3 of 8 
                  91-135 degrees 
                 1 
                 1 
                 1 
               
               
                 1-4 of 8 
                 136-180 degreees 
                 1 
                 0 
                 1 
               
               
                 1-5 of 8 
                 181-225 degrees 
                 0 
                 1 
                 1 
               
               
                 1-6 of 8 
                 226-270 degrees 
                 0 
                 0 
                 0 
               
               
                 1-7 of 8 
                 271-315 degrees 
                 0 
                 1 
                 0 
               
               
                 1-8 of 8 
                 316-360 degrees 
                 0 
                 0 
                 0 
               
               
                 8 of 8 fully 
                 Fully Closed - 
                 0 
                 0 
                 0 
               
               
                 deployed 
                 360 degrees 
               
               
                   
               
             
          
         
       
     
         [0034]    The intra-section position reader  230  includes a photo-interrupter sensor  246  mounted on the plate  244  and a gear  248  coupled to the motion mechanism  250  of the door (not shown). The motion mechanism  250  and gear  248  are configured such that one full rotation of the gear  248  corresponds to the linear movement of the door through one virtual section. The gear  248  also includes a plurality of depending flags  252  for changing the state of the sensor  246 . For example, when a virtual section is 50 cm., the gear  248  has twenty-five equally sized and spaced flags  252 . Hence, by passing through a full rotation, the gear  248  will generate 50 changes of state for the sensor  246 , each state corresponding to a centimeter of door travel. 
         [0035]    In another embodiment, the door rides in a track. Accordingly, a position reading mechanism is mounted at the top of the opening. Such a position reading mechanism would include three optical interrupter sensors, each sensor aligned with a different location. Flags would extend from the door to change the state of the interrupter sensors and, thereby, segment the door into virtual sections. 
         [0036]    For example, a single flag that extends across the bottom four virtual sections could be aligned to pass through sensor A. Regarding sensor B, two flags would pass there through. One of the sensor B flags would extend across the bottom two virtual sections and the other would extend across the third and fourth sections from the top. Lastly, a series of four flags would align with sensor C, each flag extending from alternating virtual sections. An exemplary chart illustrating this sensor and flag scheme is shown below in Table 3. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Virtual Door Section 
                 Sensor A 
                 Sensor B 
                 Sensor C 
               
               
                   
                   
               
             
             
               
                   
                 1 
                 0 
                 0 
                 0 
               
               
                   
                 2 
                 0 
                 0 
                 1 
               
               
                   
                 3 
                 0 
                 1 
                 0 
               
               
                   
                 4 
                 0 
                 1 
                 1 
               
               
                   
                 5 
                 1 
                 0 
                 0 
               
               
                   
                 6 
                 1 
                 0 
                 1 
               
               
                   
                 7 
                 1 
                 1 
                 0 
               
               
                   
                 8 
                 1 
                 1 
                 1 
               
               
                   
                   
               
             
          
         
       
     
         [0037]    In still other embodiments, the sensing arrangements are different technology now known or later developed such as RFID, linear encoders, hall effect magnetic switches and combinations of the same. As would be appreciated by those of ordinary skill in the pertinent art, the functions of several elements may, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the illustrated embodiment. 
         [0038]    Also, functional elements shown as distinct for purposes of illustration may be incorporated within other functional elements, separated in different hardware or distributed in various ways in a particular implementation. Further, relative size and location are merely somewhat schematic and it is understood that not only the same but many other embodiments could have varying depictions. Additionally, each claim may depend from any or all claims in a multiple dependent manner even though such has not been originally claimed. 
         [0039]    While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims.

Summary:
A garage door assembly including a door for enclosing an opening, and a mechanism for selectively deploying the door in a closed position to cover the opening, and an open position with the door stored leaving the opening open. A position reading assembly monitors a position of the door with respect to the opening. The position reading assembly includes a controller and three switches in communication with the controller. The switches are positioned such that movement of the door actuates the three switches and, in turn, the controller divides the door into eight virtual zones between the closed and open positions.