Patent Publication Number: US-8978965-B2

Title: Spring cycle counter

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of copending parent patent application Ser. No. 12/835,992, filed Jul. 14, 2010, entitled “DOOR CYCLE TRACKER”. The aforementioned application is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to the field of spring cycle trackers. More particularly, the invention pertains to a spring cycle tracker for an overhead door. 
     2. Description of Related Art 
     Many residential homes and businesses use overhead doors. Springs are used to aid in opening and closing overhead doors. The springs are very tightly tensioned. Most springs used with overhead doors have a life of about 10,000 cycles or about 10 years of normal use, with each spring cycle being equal to one opening and one closing of an overhead door or a door cycle. A breaking spring that is not properly contained may lash out and strike people and or damage property. Currently, there is no way track the life cycle of the spring so that the springs can be properly replaced prior to them breaking and possible injuring people and property. 
     SUMMARY OF THE INVENTION 
     A spring cycle tracker system for a door mounted on a track having at least one spring and the door having an open and closed position. The system has at least one sensed element and a tracker. The tracker has a sensor having at least one sensing element; and a controller having a counter, at least one input signal from the at least one sensing element and at least one output signal. The sensed element and the tracker are mounted such that when the door is moved towards the open position and/or the closed position, the sensed element and the controller are moved adjacent to each other so that the sensing element senses the sensed element, sending an input signal to the controller, incrementing the counter, tracking a number of times the spring is used. The sensed element and the tracker are mounted at a height greater than 50% of the total height of the door when the door is in the closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a section of an interior elevation of a sectional overhead door in a closed position. 
         FIG. 2  shows a side view of the interior of a sectional overhead door in a closed position. 
         FIG. 3  shows a schematic of the cycle tracker and the overhear door moving towards an open position. 
         FIG. 4  shows a schematic of a control scheme to actuate the counter of the cycle tracker. 
         FIG. 5  shows an alternative cycle tracker. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-2  show an overhead door  2  in the closed position with a cycle tracker  12  of the present invention. The overhead door  2  includes a series of sections  4  that are connected to each other by hinges  8  near the outer edge  7  of the door and another set of hinges  6  between the sections  4  and the outer edges  7 . It should be noted that only one set of hinges  8  on the outer edge  7  and one set of hinges  6  between the outer edges  7  are shown in  FIG. 1 . Additional hinges may be present. 
     Above the overhead door is mounted a torsion spring counterbalance system. The torsion spring counter balance system includes a torsion spring  22  on a torsion shaft  20  mounted over the overhead door with a winding cone  19  on one end and a stationary cone (not shown) at the other end. At the ends of the torsion shaft  20  are cable drums  18 . Counterbalance cables  23  run from the vertical tracks at the bottom corners of the door to the cable drums  18 . 
     The outer edges  7  of the sections  4  of the overhead door  2  are mounted on a vertical track  10 . The vertical track  10  transitions into a horizontal track  24  as shown in  FIG. 2 . In one embodiment, attached to the vertical track  10  of the overhead door  2  is reflective tape  17  or some other type of reflective material. Attached to an outer edge  7  of one of the sections  4  of the overhead door is a cycle tracker  12 . The cycle tracker  12  tracks the number of door cycles or spring cycles which can be used to predict the remaining life or the remaining number of life cycles of the spring. One spring cycle is equivalent to one door cycle, with each door cycle equal to one opening and closing of an overhead door  2 . 
     By knowing the approximate life cycle of the spring, through tracking the number of times the spring has been used or the number of cycles that have already taken place through the number of door cycles, the remaining life cycle of the spring may be predicted and the torsion spring can be replaced prior to it breaking or snapping, decreasing the possibility of injuring people and property. 
     An audible alarm of the cycle tracker  12  may sound a warning, indicating when the torsion spring is approaching a certain percentage of life remaining, or may also be set when the number on the counter exceeds a specific number of spring cycles. For example, the alarm may sound a warning if 20% of the life cycle of the spring remains or if the counter exceeds 8000 spring cycles. Additionally, the cycle tracker  12  may also have, either separately or in conjunction with the audible alarm, a visible alarm in the form of a light to indicate when the counter reaches a specific number of spring or door cycles. 
     Referring to  FIG. 3 , the cycle tracker  12  includes a body or plate  11  that is mounted the outer edge  7  of a section  4  of the overhead door  2 . A counter  14 , which is preferably part of a controller  34 , preferably has at least six digits visible and is actuated to increment by the controller  34 . The controller  34  is not limited to the inputs and outputs shown within the drawings. The counter  14  is preferably resettable and may be digital. 
     As shown in  FIG. 4 , within the cycle tracker  12  is a sensor  30  which contains both an emitter  33  and a sensor receiver  36 . The sensor  30  may be a diffuse-mode sensor, where light emitted from the sensor strikes the surface of an object to be detected (in this case the reflective tape  17 ), and is diffused back or sends some light back to the receiver  36 . Therefore, the reflective tape  17  is detected when the beam of light  32  hits the reflective tape  17  and reflects back the sensor&#39;s transmitted light energy back to the sensor. Other type sensors, such as a retroreflective sensor, divergent-mode sensors, or convergent-mode sensor may also be used. 
     When the reflective tape  17  is detected, the sensor  30  sends an input signal to a controller  34 . The controller  34  increases the counter  14  by 0.5. If the number on the counter  14  exceeds a preset number, the controller  34  sends an output signal to an alarm  35 . The alarm  35  may be a visual alarm, an audible alarm or both. Both the alarm  35  and the counter  14  may be resettable. 
     Looking, then, at a complete door cycle from closed, to open and back to closed, the counter system works as follows: 
     When the overhead door  2  is raised to an open position, the torsion spring  22  unwinds and the stored tension aids in lifting the sections  4  of the overhead door  2 . The wheels on the sections slide inn the vertical track  10  and transition onto the horizontal track  24 . The spring  22  takes up the weight as the door moves by turning the shaft  20 , thus turning the cable drums  18 , wrapping the cables  23  around the cable drums  18 . 
     As the overhead door  2  is moving onto the horizontal track  24 , the cycle tracker passes the reflective tape  17 . Light emitted from the sensor  30  of the cycle tracker  12  strikes the reflective tape  17 , and reflects back the sensor&#39;s transmitted light energy back to the sensor  30 . The sensor  30  sends an input signal to the controller  34 . The controller  34  increases the counter  14  by 0.5. If the number on the counter  14  exceeds a preset number, the controller  34  sends an output signal to an alarm  35 . 
     To close the door from the open position described above, the overhead door  2  is lowered to a closed position in which an edge of one of the sections  4  is in contact with the ground  3 . In the closed position the sections  4  of the overhead door  2  are on the vertical track  10 . As the door closes, the cables  18  unwrap from the drums  18  and the torsion spring  22  is rewound to full tension. 
     As the overhead door  2  is moving towards the closed position, the cycle tracker once again passes the reflective tape  17 . As it does, light emitted from the sensor  30  of the cycle tracker  12  strikes the reflective tape  17 , and reflects back the sensor&#39;s transmitted light energy back to the sensor  30 . The sensor  30  sends an input signal to a controller  34 . The controller  34  increments the counter  14  to increase the counter by 0.5. If the number on the counter  14  exceeds a preset number, the controller  34  sends an output signal to an alarm  35 . 
     Thus for each complete cycle of door opening and door closing, the counter is increased by 0.5 twice—therefore, one complete door cycle of an opening and closing of the door increases the counter by one. One door cycle is equivalent to one spring cycle. 
     In an alternate embodiment, the cycle tracker may only track when the door is moved to an open position. 
     The cycle tracker  12  is preferably attached to a section  4  of the overhead door  2  at eye level of a user or greater than 50% of the height of the door when the door is in the closed position. 
     In another embodiment of the present invention, the spring cycles may be tracked when the door is moving in only one direction (up or down) by placing two separate sensors  30  with two separate sensing or receiving elements  36  at different locations offset from each other. The two receiving elements  36  provide input to a controller  34  within a cycle tracker  12 . In other words, two reflective strips  17  horizontally and vertically offset in the door track  10 ,  24  are sensed, and only counted when a first receiving element of a first sensor detects the reflective material before the second receiving element of a second sensor, indicating that the door is moving in a selected direction. When this occurs, the counter is increased by one by the controller  34 . 
     In another embodiment which would allow the counting to only occur when the door is moving in one direction, the reflective material  17  could be patterned to have non-reflective portions in a specific pattern, such that when a sensor receiver  36  receives transmitted light from the reflective material  17  and the overhead door  2  is moving one way—for example, towards an open position—the sensor  30  would sense light transmitted or reflected in a pattern such as on-off (long)-on-off(short)-on. When overhead door  2  is moving in the other direction—towards a closed position—the light transmitted to the sensor  30  or reflected in a different pattern such as on-off(short)-on-off(long)-on. By being able to determine which way the door is moving, the counter  14  can be incremented either for both opening and closing, or just if the door is moving in one direction, open or closed. 
     In an alternate embodiment, the reflective material  17  may be replaced by a magnet  50  as shown in  FIG. 5 . The counter  14  would be actuated when the overhead door  2  approached the magnet  50  and actuated a switch  51  to complete the circuit  53  within the cycle tracker  52 . A controller  34  includes a counter  14  to monitor the number of door cycles or spring cycles and send a signal to trigger an alarm. 
     In another embodiment which would allow the counting to only occur when the door is moving in one direction, magnets  50  may be placed horizontally and vertically offset on each door track at different heights, and the counter  14  is only increased when a first sensor detects the magnet before a second sensor detects the magnet. 
     While the drawings and the discussion above have the cycle tracker  12  mounted on the overhead door  2  and the sensed element (reflective material  17  or magnet  50 ) mounted at a fixed location near or to the track, it will be understood that the invention contemplates simply that the two elements be mounted at locations where a moving element (be it the tracker or the sensed element) passes by the fixed element (the other of the sensed element or the tracker). Therefore, the opposite arrangement to that discussed previously is also possible, in which the cycle tracker  12  is mounted to a fixed location adjacent to the door—either on the vertical track  10  or on the horizontal track  24  or at a location adjacent to one of the tracks—and the sensed element is mounted to the moving overhead door  2 . In such an arrangement the sensed element (reflective material  17  or magnet  50 ) would be preferably attached to a section  4  of the overhead door  2  at eye level of a user or greater than 50% of the height of the door when the door is in the closed position. 
     While a digital counter is described, other types of counters that may be electrically or electronically actuated may also be used. 
     While the cycle tracker  12  was described and shown in reference to an overhead door  2  with a torsion spring counterbalance system, one skilled in the art could be expected to apply the cycle tracker to an overhead door with extension springs. 
     While the overhead door was shown as being comprised of segments, the door may also be of the type that lifts in one piece. 
     Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.