Patent Publication Number: US-7583040-B2

Title: Motorized closure operating device with electronic control system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority on U.S. Provisional Patent Application Ser. No. 60/721,997 filed Sep. 30, 2005, the entire contents of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a motorized operating device for an overhead closure, and, more particularly, to a motorized closure operating device with an electromechanical or electronic control system. 
     BACKGROUND OF THE ART 
     Overhead closures or barriers are well known and used in a variety of applications including, but not exclusively, garage doors, room dividers and the like. Most such closures are operated (i.e. opened and closed) by way of an electric motor, which is typically actuated by remote control, proximity sensors and/or by a suitable switch mounted near the closure, such as a push-button or key-pad for example. 
     Such closures also commonly include obstacle detection systems which prevent the closure from closing completely if an obstacle is present in its travel path. Such sensing features include a sensing edge located along the bottom edge of the closure which detects contact with such an obstacle and signals the electric motor to stop the movement of the closure and/or reverse the direction of travel thereof. Light beam based photo-switches are also used to similarly stop and reverse the closure direction in the event of an obstacle in the travel path of the closure. 
     However, as the closure reaches its predetermined end travel limit position (i.e. the position at which the closure is to stop in order to seal the opening closed off by the closure), such sensing features which normally reverse the direction of travel of the closure must be temporarily deactivated, so as to not undesirably re-open the closure when it is to remain closed. 
     Such a temporary deactivation of the sensing features is normally called the “advance close” feature of the operating device. Commonly, this is achieved mechanically using a mechanism located within the operating device which includes a two-step activation switch and a displaceable lever which acts thereon. For example, such a mechanism would operate as follows. Shortly before the closure reaches its fully closed position, the internal lever acts against a first switch to depress the actuating button thereof, thereby activating the advance close feature (i.e. temporarily deactivating the sensing features) such as to prevent the sensors from inopportunely reversing the door travel direction upon reaching the fully closed position. Once the closure reaches its “advance close” position, the lever is further displaced to depress a second switch that requires greater actuating button travel, i.e. in order to thereby fully stop all movement of the closure. Alternately, a single stop switch may be used, which has a two-tiered stop button travel. Typically, the displaceable lever is acted upon by a cam disk which translates along an endless screw within the operating device in accordance with the position of the closure. 
     One problem with the above-described mechanically operated advance close feature typical of most closure operating devices resides in the lack of adjustability and control that they provide. Further, they necessitate careful setup and make adjusting the full stop position of the closure, and particularly fine tuning the advance close position thereof, difficult. For instance, if the device has been configured to be installed within an opening such that the closure will travel at a given speed, but an alternate speed, and therefore location of the deactivation of the sensing features, is in fact required, careful readjustment of the relative positions of the lever and cam disk location of the mechanism within the operating device must be performed. Further, this also necessitates a relatively complex two-stage switch used to stop the electric motor driving the closure. 
     An improved closure operating device is therefore sought. 
     SUMMARY OF THE INVENTION 
     It is therefore an aim of the present invention to provide an improved closure operating device. 
     Therefore, in accordance with one aspect of the present invention, there is provided a closure operating device for opening and closing an overhead closure, the closure operating device comprising: a motor operatively connected to an output shaft for rotation thereof, said output shaft being adapted to drive said closure for displacement thereof along a travel path between open and closed limit positions; a sensing system operable to at least one of stop and open the closure upon detection of the presence of an obstacle obstructing the travel path of said closure; a control system in communication with said motor and said sensing system, said control system including a control unit operable to deactivate said sensing system at a selected point prior to said closed limit position of said closure; at least one switch in communication with said control system and actuable by a switch actuator, the switch actuator being displaceable along the output shaft and operable to actuate said switch when disposed in a predetermined position therealong; and wherein the control system determines one of said selected point for the deactivation of the sensing system and the closed limit position of the closure, based on a delay period relative to the actuation of said switch. 
     There is also provided, in accordance with another aspect of the present invention, an operating device for an overhead closure, the operating device comprising: a motor operatively connected to said closure for opening and closing the closure; at least one sensor unit mountable to one of the closure and a support surface bordering the closure, the sensor unit being operable to detect the presence of an obstacle obstructing a travel path of said closure and to generate a signal in response thereto; and a control system in communication with said sensor and with said motor, said control system including a control unit which receives said signal and provides a sensing feature which at least one of stops and opens the closure in response to said signal, said control unit deactivating said sensing feature at a selected point prior to an end limit position of said closure, the selected point being determined by the control unit based on a calculated delay characteristic. 
     In accordance with a further aspect of the present invention, there is provided a method of controlling operation of a closure using an electronic control system, the method comprising: using a sensing system to determine the presence of an obstacle obstructing a travel path of the closure and to at least one of stop and open the closure when the presence of said obstacle is detected; determining a selected position of the closure below which obstacle detection using the sensing system is not required, and using said electronic control system to calculate a delay characteristic corresponding to said selected position of said closure; and deactivating said sensing system using said control system based on said delay characteristic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which: 
         FIG. 1  is a perspective view illustrating a conventional overhead closure, such as a garage door, equipped with an operating device for opening and closing the closure; 
         FIG. 2  is a lower perspective view of a closure operating device in accordance with the present invention; 
         FIG. 3  is a schematic top plan view of the operating device of  FIG. 2 ; and 
         FIG. 4  is a partial top perspective view of the operating device of  FIG. 2 , showing the limit switches and the switch actuating elements which are displaceable along a rotating shaft of the device. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In  FIG. 1 , an overhead closure C, such as a garage door, room divider, etc. includes in this case four sectional panels P hinged together by hinges H to allow relative pivots of the panels P one to the other when they are driven, manually or by way of a operating device  10 , along a pair of lateral guide rails R. The operating device  10 , although shown mounted at the edge of closure C, can similarly be centrally mounted relative to the closure, i.e. between each of the laterally spaced guide rails R. The operating device  10  preferably includes an electric motor, as described in further detail below, however manual operation of the closure C remains possible by decoupling the driving motor of the operating device  10  such that a user can manually open and close the closure C, such as by using chain driven pulleys, for example, with or without a speed reduction. Speed reduction can be achieved using a belt and pulley drive system, or alternately a suitable gearbox. 
     Referring to  FIG. 2 , the closure operating device  10  for opening and closing an overhead closure, such as the garage door C depicted in  FIG. 1  for example, generally comprises a support structure and outer casing  12  defining an internal space therewithin, within which most elements of the closure operating device are contained with the exception of the protruding output shafts and transmission elements of the drive system of the device. Preferably, the operating device  10  is driven by an electric motor  14  mounted within the casing  12 . As will be described further below with regard to  FIG. 3 , the output shaft of the electric motor  14  is operably connected to the operating device output shaft  16 , which is journaled within the spaced apart lateral walls  18  of the casing  12 , via a transmission  20  (not seen in  FIG. 2 ). The transmission  20 , as best seen in  FIG. 3 , generally includes a driving pulley  22  mounted on the motor output shaft  21  which is interconnected by a belt  25  with a driven pulley  24  mounted on the output shaft  16 . By selecting the pulleys  22  and  24  having different diameters, a speed reduction or speed increase is achieved. It is understood that the transmission  20  can alternately include a chain interconnecting driving and driven sprocket gears, in lieu of the pulley and belt system, and further that if desired, no gear up or gear down of the motor output need be provided. 
     Referring now to  FIG. 3  in more detail, the driven pulley  24  of the transmission  20 , which may include an integral clutch mechanism disposed therein, is fixed to a first end  26  of the output shaft  16  such that no relative rotation therebetween is possible. This may be achieved by any suitable means such as a keyed interconnection, for example. At an opposed end  28  of the output shaft  16 , disposed on an opposite outer side of the casing walls  18 , is fixed a sprocket  30 . The sprocket  30  may be interconnected with a chain drive system to provide the rotary output from the device, or alternately rotation of the output shaft of the operating device may be used to drive a separate gear, sprocket and/or pulley for interconnection with the closure to translate rotation of the output shaft  16  into displacement of the closure within its lateral guide rails R between the open and closed limit positions of the closure C. The sprocket  30  on the output shaft  16  of the operating device is preferably interconnected, via a flexible transmission element such as a chain or toothed belt, with a second sprocket  32  that is fixed to the control shaft  34  in alignment with the sprocket  30  on the output shaft  28 . The co-operating sprockets  30  and  32  are, in the depicted embodiment, interconnected by an endless chain  36 . In this embodiment, the output shaft  16  of the operating device  10  is rotatable by the motor  14  in either direction in order to open and close the overhead closure to which it is operably connected, for displacement of the closure between open and closed limit positions. 
     As best seen in  FIG. 4 , at least one switch is mounted within the casing  12  of the operating device  10  and disposed in communication with at least the motor  14  in order to stop and start the motor as required in order to control movement of the closure. In the depicted embodiment, two control switches are provided, namely an “open” limit switch  38  and a “close” switch  40 . Each of the switches, when actuated, either act to directly cut all power to the electric motor  14  in order to stop movement of the closure at either of the respective end limit positions when used as a end limit point switch or, alternately, act to deactivate the sensing systems when used as an advance close point switch, as will be discussed in further detail below. Each switch includes a contact element  42  which, when displaced by a switch actuator, acts to operate the switch thereby interrupting current to the electric motor. The switch actuators preferably comprise a pair of displaceable cam discs, including an open cam  44  and a close cam  46  which are spaced apart on the control shaft  34 . The control shaft  34  is preferably threaded on its outer surface, and the cams are prevented from rotating by a traveling-cam retaining bracket  47 , which is received within radially extending slots  45  in each of the open and close cams  44 ,  46  and retained in contact therewithin by a pair of opposed biasing members, such as helical coil springs  49 . As such, the open and close cams  44  and  46  are axially displaceable along the control shaft  34  when the shaft is rotated and remain the same distance apart once their position on the control shaft  34  is set. Therefore, by rotating the control shaft  34 , the open and close cams  44  and  46  are forced to axially displace along the length of the control shaft. When either of said cams abut the contacting element  42  of either of the limit switches, power to the electric motor is interrupted, thereby stopping movement of the closure. When the operating device is not running, the traveling-cam retaining bracket  47  may be manually withdrawn from contact with either or both of the cams in order to manually adjust the relative position of each of the cams on the control shaft  34 , thus permitting adjustment of the open and closed limit positions of cams on the shaft, and therefore of the overall travel of the closure. Particularly, manually rotating the cam on the stationary control shaft  34  towards the center of the shaft will increase door travel while turning the cam such that it is displaced laterally outwards, towards the corresponding switch, will decrease door travel. 
     In prior art closure operating devices, three or four limit switches are commonly employed, particularly an open and close limit switch as well as an advance open and an advance close limit switch. The advance close limit switch is used to temporarily deactivate any closure reversing devices or other sensing devices or systems which normally act to stop or reverse direction of the closure in the event of the detection of an obstacle within the closure travel path. Thus, the advance close feature permits such sensing systems to be deactivated slightly before the closure reaches its fully closed position, thereby preventing the closure from reversing when the floor is reached in fully closed position. However, such advance open and close limit switches add further parts to the operating device and provide only very limited adjustment capabilities. Thus, each switch in such prior art devices provides only a given predetermined advance close distance, which typically cannot be readily modified by the end user. The closure operating device  10  of the present invention disposes of at least such a separate advance close switch, as will be described in greater detail below. 
     Referring back to  FIG. 3 , the closure operating device  10  of the present invention further includes a sensing system  51  which includes a controller  52 , which is disposed at least in communication with a control system  50  (described further below) and which may be integrated directly within the control system  50 , which is operable to at least one of stop and reverse travel direction of the closure in response to a signal received from a sensor unit  61  (see  FIG. 1 ) of the sensing system  51 . Such a sensor unit  61  may include any suitable sensor such as, for example, a reversing edge  60  (see  FIG. 1 ) disposed along a lower edge of the closure, a loop detector and/or a photocell sensor. The sensor unit  61  can be mounted either directly to the door or to a wall or support surface adjacent the opening that the closure closes off, depending on the type and nature of the selected sensor. The controller  52  of the sensing system  51  therefore receives signals from a sensor unit  61  which is capable of indicating the presence of an obstacle obstructing the travel path of the closure, and is operable to instruct the motor (either directly or via the control system  50 ) such that the sensing system is able to stop or reverse travel direction of a closure in response to this signal. 
     The operating device  10  includes a control system  50  which is in communication with both said sensing system and the motor  14 , and which is used for controlling all sensing functions of the device. Therefore, the control system  50  is operable to activate the immobilization and reversal of travel direction of the electric motor  14 , and therefore of the closure operably connected thereto, in the event of the receipt of a signal from the sensor indicating the presence of an obstacle obstructing the travel path of the closure. The control system  50  includes a control unit, which can include a microprocessor and/or an electromechanical control system. 
     The control system  50  is preferably an electronic control which includes a circuit board based electronic system having a microprocessor  54  which is programmed to, inter alia, deactivate the above mentioned sensing system at a selected point prior to at least the fully closed limit position of the closure. A sensing operating mode is defined when the sensing system is active, while a free operating mode is defined when the sensing system is deactivated. The electronic control system thus is able to switch between these two modes during travel of the closure. Accordingly, the functions previously carried out in prior art systems by a pair of advance open and close switches are fully digitally controlled by the microprocessor  54  of the electronic control system  50 . Preferably, the determination of the selected point prior to the fully closed limit position of the closure can be calculated by the microprocessor  54  based on a given delay characteristic which is determined by the microprocessor or alternately manually selected and/or programmed by the user. This delay characteristic is calculated, for example, based on rotational speed of the electric motor  14 , rotational speed of any of the rotating shafts of the device (including the output shaft  28 ), and a calculated time period which is dependent on the known descent speed of the closure. One or more of these factors may be employed by the control system  50  in order to determine a suitable point, prior to the fully closed position of the closure, at which it remains acceptable to deactivate the sensing features of the entire system. For example, this predetermined point (i.e. the advance close point) may correspond to several inches above the floor or ground on which the closure abuts once it has reached its fully closed limit position. 
     The advanced close point, or rather the distance and/or travel time of the closure either before or after it, can be determined by the microprocessor of the control system based on various input factors on which it depends, such as rotation speed of the motor and the corresponding decent speed of the closure in addition to total travel distance (or time) thereof. Thus, the control system  50  is able to calculate the corresponding time it takes for the closure, traveling at a known descent speed resulting from the known or measure rotational speed of the motor and the intervening transmission, to travel between a selected sensing system deactivation point and the closure&#39;s fully closed position. This time period may be calculated in a number of ways, for example this time period may be calculated by the microprocessor  54  by determining a first time taken by the closure to travel from the fully open limit position to the fully closed or end limit position, and subtracting therefrom a second smaller time interval corresponding to the time required for the closure to go from the fully open position to the selected predetermined deactivation point of the sensing system. Thus, the control system  50 , and more particularly the microprocessor  54  thereof, is programmable to calculate and determine either the selected point at which the sensing systems are to be deactivated prior to reaching the fully closed limit position of the closure or the point at which the fully closed position has been reached following an indication that the sensing system deactivation has occurred, and to communicate with the sensing system in order to actuate said deactivation thereof or with the motor to stop operation thereof. The control system  50  may thus directly cut power to the motor, thereby immobilizing the closure, such as once the closure has reached the determined fully closed position thereof. This may be determined based on a calculated time that the closure will take to reach the fully closed position. Thus, for example, the control system  50  can be used to calculate the determined time delay necessary for the closure to reach the selected advance close (sensing system off) point from the initial or fully opened position. Once this point has been reached by the closure, the control system deactivates the sensing systems. Knowing the full travel time required by the closure to reach the end limit position, the control system can then determine the remaining time between the advance close position and the end (fully closed) limit position, and stop all movement of the closure by cutting power to the motor once this remaining time has expired. Other means of calculating the selected advance close position at which time the sensing systems will be deactivated, as well as the complete immobilization of the closure, can be performed using the micro-controller-based electronic control system  50 . 
     In one embodiment, the close switch  40  is used as a sensing system cut-off (or advance close) switch, whereby when the displacing close cam  46  actuates the switch  40 , the switch communicates with the control system  50  to deactivate the sensing systems. The control system  50  is then configured to allow the motor to run only for a predetermined time period following this advance close point before power to the motor is cut off and therefore movement of the closure is fully stopped. In this embodiment, therefore, the control system is pre-set to allow an appropriate time period, corresponding to the desired distance between the advance close (i.e. sensing system shut-off) point and the appropriate fully closed limit position of the closure, to elapse before the motor is shut off. As above, the motor can be shut off by the control system either by directly cutting power to the motor or by sending a signal to the motor that power is to be shut off. The appropriate time between the advance close point and the fully closed point will vary depending on the travel speed of the closure, and therefore can either be calculated by the control system or predetermined and set by a user. 
     In this embodiment, the system operates as follows. As the closure moves along its travel path towards the closed position thereof, whereupon a displacing switch actuating member (in the form of the close cam  46 ) will eventually actuate the switch  40  at a selected predetermined advance close point, typically only a few inches before the fully closed position of the closure. Once this switch has been actuated, the control system deactivates the sensing systems but allows the motor to continue to run a determined period of time following this advance close switch actuation. Once this determined period of time has elapsed, the motor is shut off and the closure therefore stops in its fully closed position. In one possible embodiment, during the count-down of this determined period of time, the sensing systems are not operational and thus movement of the closure cannot be stopped or reversed in direction thereby. In another alternate embodiment, however, the sensing systems remain operational during this determined period of time. The control system thus nevertheless shuts off the motor after the expiry of this determined time period, however if one of the security measures is activated during this time (in the event of the detection of an obstacle in the travel path), the closure can still stop and/or reverse directions. 
     Preferably, the control system  50  further includes a manual adjustment element  56 , which may be either mounted directly on a circuit board of the control system  50  or alternately may be externally mounted on the operating device  10 , such that the user is able to manually adjust and select the point of the closure travel at which the sensing systems are to be deactivated prior to reaching the end limit position. The manual adjustment switch  56 , for example mounted on the circuit board of the control system  50  within the casing  12  of the operating device, may include a coded rotating selector switch or a multi switch selector for example, configured such that the user can select one of several different predetermined delay characteristics. Thus, adjustment of the selected point at which the sensing systems are deactivated, and/or the time between this deactivation point and the fully closed position, can be manually varied by the user or technician in situ. Other suitable types of switches can also be used. This can also be achieved by electronically linking an external computer with the control system  50 , in order to digitally change any one of a plurality of variable characteristics (such as closure travel speed, rotational motor output speed, time delay for deactivation of the sensing systems, etc.) which are preprogrammed therewithin. The control system may, for example, include a programmable logic circuit (PLC) that can be modified as required, either remotely or directly via the control system mounted within the operating device, in order to change such variable characteristics. 
     The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, although the control system is described as employing a programmed/programmable microprocessor to control operation of the sensing system deactivation, the control system  50  may include, alternately or additionally, an electromechanical control system having relays and condensers, by a time-based relay system, or the like. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.