Patent Publication Number: US-7591102-B1

Title: Emergency door opening actuator

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention generally relates to an emergency actuation system for overhead doors, and specifically to an emergency door opening actuator that causes an automatic overhead door to open in case of a fire or associated high temperatures. 
     2. State of the Art 
     Fire doors with actuators that cause the doors to close in emergency conditions are known. These fire door systems generally close overhead doors under the influence of gravity. Many such doors have fusible links that melt and break at temperatures above a certain range. These door systems thus have mechanical door closing actuation mechanisms and mechanical closing mechanism. Some fire doors have been developed that have electric powered door closing mechanisms and electronic door closing actuation mechanisms. 
     Other door systems have been developed for assuring ventilation when a high level of a toxic gas such as carbon monoxide has been detected. Once again, these doors systems include electronic sensors and actuate a door open when a minimum level of carbon monoxide or other gas is detected 
     There is a deficiency of devices for assuring egress from a garage or house through the garage door. Several persons including fire fighters have lost their lives or been severely injured by being trapped in a garage during a fire. These deaths and injuries continue to occur, indicating a need in the art for a simple, inexpensive, yet failsafe device that will cause an overhead door to open and allows egress in the case of a fire. 
     DISCLOSURE OF THE INVENTION 
     The present invention relates to emergency door actuation systems for overhead doors in general, and specifically to an emergency door opening actuator that causes an automatic overhead door to open in case of a fire or associated high temperatures. 
     An emergency door opening actuator in accordance with the present invention may include electrical switches that are at least one of normally open and normally closed. These electrical switches may be connected accordingly in parallel or in series to terminals of an overhead door operator. The terminals may correspond to a push button circuit, an obstruction sensing circuit, and/or an alarm system circuit. The operator may have an existing protocol for responding to signals from a push button circuit and an obstruction sensor circuit. Thus, the emergency door opening actuator may take advantage of the protocol to cause the overhead door to open during an emergency condition to facilitate egress. Likewise, the emergency door opening actuator may cause that the overhead door cannot close. This is achieved by signaling the protocol in a predetermined way when the switches are actuated by an emergency condition. The electrical switches may be mechanically actuated when at least one fusible link is broken. 
     In a simple form, an emergency door opening actuator may include a switch actuator movable between a first position and a second actuation position. The switch actuator may engage an electrical switch in the first position. The switch actuator may be coupled to at least one fusible link. The switch actuator may also be coupled to an anchor that is adapted for mounting to a structural member of a building/house. The fusible link may be configured such that when it breaks, the switch actuator moves to its second position and releases the electrical switch. 
     The fusible link may be one of a plurality of fusible links. The door opening actuator may further include a sash that includes the fusible link and couples the switch actuator to the anchor. The plurality of fusible links may be located at key locations in the building/house for release of the sash during fires or high heat in the key locations. 
     The emergency door opening actuator may include a housing that supports one or more of the switch, the switch actuator, and a spring. The housing may have a mounting structure thereon adapted for attachment of the housing on a structural member proximate to an automatic door operator. 
     In another simple form, the present invention may include a method of causing an overhead door to automatically open during an emergency. The method may include mechanically coupling a switch actuator to at least one fusible link, and connecting at least one electrical switch to at least one terminal of an automatic door operator to transmit an indication to the operator similar to that which is received from a button circuit when an automatic door operator button is pressed. This aspect of the invention may also provide one or more aspects of a method of installing and/or a method of manufacturing. The method of causing the overhead door to automatically open may include engaging the electrical switch with the switch actuator in a non-emergency state. The method may also include disengaging the switch actuator from the switch and releasing the electrical switch when the fusible link is broken by a predetermined temperature. As may be appreciated, the method may include connecting a plurality of switches to a plurality of terminals in the automatic door operator to transmit indications similar to one or more of an indication that the button has been pressed, that an obstruction has been detected, that an alarm condition exists, and that the door must be raised. 
     The method of causing the overhead door to automatically open wherein the fusible link is integral with the sash may include anchoring a distal end of the sash to a point in a building/house, connecting a proximal end of the sash to the switch actuator, and holding the switch actuator in a non-emergency position against a bias of the switch actuator. The method of causing the overhead door to automatically open may include distributing a plurality of fusible links at selected positions on the sash for response to high temperatures at the selected positions in the building/house. In one case the method may include locating a first of the fusible links proximate the operator and locating a second of the links on an opposite side of a wall from the operator. The method may also include locating at least one of the fusible links at a remote location within the building/house. 
     In another simple form, the present invention may include an emergency door opening operator having an overhead door operator for raising and lowering an overhead door. A switch actuator may be movable between a first position and a second actuation position in the actuator. The switch actuator may engage an electrical switch in the first position. The switch actuator may be coupled to at least one fusible link as described above. The switch actuator may be coupled to an anchor that is adapted for mounting to a structural member of a building/house. In this way, the electrical switch may be connected to at least one terminal of the overhead door operator. Furthermore, the fusible link may be configured such that when it breaks, the switch actuator moves to its second position and releases the electrical switch. 
     The at least one terminal may be one of a plurality of terminals connected to a plurality of indication circuits in the overhead door operator. The electrical switch may be one of a plurality of electrical switches that are connected to the plurality of terminals of the operator. The fusible link may be configured such that when it breaks, the switch actuator moves to its second position and releases the plurality of electrical switches. 
     The foregoing and other features and advantages of the present invention will be apparent from the following more detailed description of the particular embodiments of the invention, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an emergency door opening actuator incorporated with an operator and overhead door system according to an embodiment of the present invention; 
         FIG. 2  is a side view of the operator and the emergency door opening actuator of  FIG. 1 ; 
         FIG. 3  is a sectional view of the emergency door opening actuator taken along line  3 - 3  of  FIG. 2 ; 
         FIG. 4  is an end view taken in a direction of arrow  4  of  FIG. 3 ; and 
         FIG. 5  is a diagrammatic view of the emergency door opening acutator and operator configured according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     As discussed above, embodiments of the present invention relate to emergency actuation systems for overhead doors in general, and specifically to an emergency door opening actuator that causes a door to open in case of a fire or associated high temperatures. 
       FIG. 1  shows an emergency door opening actuator  10  incorporated with an automatic door opening system  12  for causing a door  14  to be opened in case of a fire. The door opening actuator  10  may be mounted to an operator  15  of the automatic door opening system  12  or to proximal structural members that are part of or connected to a building in which the door opening actuator is to be used. It is to be understood that references to building herein include residential homes. 
     As shown, at least one line  18  may extend from the door opening actuator  10  and be connected to a terminal strip  21  to which the push button circuit  24  and the obstruction circuit  27  may also be connected. As may be appreciated, the push button circuit  24  connects the operator  15  to the push button  28  that may be pressed by a user of the automatic overhead door system  12  in a conventional manner. Furthermore, the obstruction circuit  27  includes an optical sensor  29  for detection of an obstruction in a conventional manner. The connections of the line  18  to the terminal  21  may be advantageously made to effectuate the functions of the present invention as will be described in greater detail below. 
     A sash  30  may couple the door opening operator  10  to one or more fusible links  33  that help make up the sash  30 . The sash  30  is also for the purpose of coupling the door opening actuator  21  to an anchor  36 . It is to be understood that the sash  30  may be any one of a number of flexible elements such as, rope, wire, cable, or chain. The sash  30  may include rigid linkages that may be formed of rods, channel members, bars, posts, or levers. The sash may also include one or more tension adjusting mechanisms and removable links. The sash may include any combination of the above described elements. 
     The operator  15  and the door opening actuator may be suspended from exposed rafters  39 , or rafters  42  enclosed behind a drywall ceiling  45  in a known manner. The sash  30  may be extended through an opening  48  in the drywall ceiling. Furthermore, the sash  30  may be extended through any number of walls through out the building and may be routed around corners by rollers  31  or eye bolts to enable selective placement of additional fusible links  33  at any location throughout the building. Thus, the sash  30  will be released when a fire or associated high temperatures are experienced at any of the locations. 
       FIG. 2  is a side view of the operator  15  and door opening actuator  10  of  FIG. 1 . As shown, the operator may have a mounting flange  51  fastened to one or more suspension member  54 , or may be mounted in any conventional manner. The door opening actuator  10  may also be mounted to the mounting flange  51 . The door opening actuator  10  may be at least partially supported in an attractive housing that may be powder coated with a fire resistant paint. The door opening actuator  10  may thus become substantially integral with the operator  15  and the overall door opening system  12 . In fact, the door opening actuator may be incorporated directly within the operator housing and may be made part of an operator by a manufacturer. This is due, in part, to the door opening actuator&#39;s complete compatibility with the operators available on the market today. 
     The terminal strip  21  may be exposed or may be enclosed in the operator  15 . Thus, the terminal strip  21  is shown in a manner that may be considered schematic in  FIG. 2 . The line  18  may include a sheath that encloses a plurality of wire pairs that may be connected to the terminals of the terminal strip  21 . A first pair of wires  57  may be connected in series to a pair of wires  59  forming the push button circuit  24  when the push button circuit is a normally closed circuit. (A series connection with the obstruction sensor circuit  27  is shown in  FIG. 2 .) Alternatively, the first pair of wires  57  may be connected in parallel to a pair of wires  59  forming the push button circuit  24  as shown by connections at the two left most terminals in  FIG. 2  when the push button circuit  24  normally operates as an open circuit. A second pair of wires  61  may be connected in series with a pair of wires  63  forming the obstruction sensor circuit  27  since the obstruction sensor circuit  27  normally operates as a closed circuit. It is to be understood that series or parallel connections may be applied depending on whether the circuit to which the respective switches are to be connected normally operate as closed or opened circuits. As such, a third pair of wires  65  may be connected in series or parallel with a pair of wires  67  forming an alarm circuit. Another pair of wires  69  may be provided in additional to or in substitution of the other pairs. The pair of wires  69  may be connected to terminals that are connected to logic and/or protocol configured specifically for preferentially sending a door  14  open in the case of an emergency. This logic and/or protocol may be provided in the operator by the manufacturer similar to the protocols for each of the other circuits to which the other terminals are connected. That is, the terminals shown in dashed lines in  FIG. 2  may be a pair of terminals dedicated to the safety function of the present invention. Thus, in the event that a manufacturer wishes to implement the advantages of the present invention directly into a particular operator, doing so may be accomplished by including the door opening protocol and an internal or external connection analogous to the terminals shown in dashed lines for connection to wires analogous to wires  69  connected to a door opening actuator. This may be done in addition to (for reduncancy), or in place of the rest of a door opening actuator analogous to door opening actuator  10  that is to be connected to the other terminals and to the other circuits including the push button circuit  24  and the obstruction sensor circuit  27 . 
     The pairs of wires  57 ,  61 ,  65 , and  69  are connected to respective electrical switches  71 ,  73 ,  75 , and  77  shown in  FIGS. 3-5 . The switches may have two switches housed together as shown in  FIGS. 3 and 4 . In this case, pressing button  79  actuates both switches  71  and  73  simultaneously. Pressing button  81  may actuate both switches  75  and  77  simultaneously. As shown, a spring  84  may be secured to a housing  87  and to a switch actuator  90  for biasing the switch actuator toward a position in which it does not engage the buttons  79  and  81 . On the other hand, the switch actuator could take any of a number of forms and may be moved into its non engaging condition by any of a variety of biasing mechanisms including under the force of gravity. While  FIGS. 3 and 4  depict the switch actuator as including an actuation lever  90  that is pivoted on a pin  93 , the switch actuator may alternatively take the form of a plunger or other movable mechanism that is capable of moving between two positions.  FIGS. 3 and 4  also show intermediate spring levers  96  and  99  that are moved by the actuation lever  90  and engage the buttons  79  and  81  in a resilient manner. These spring levers  96  and  99  thus have the advantage of protecting the switches  71 ,  73 ,  75 , and  77  against forces from a rigid switch actuator that may be too great and cause damage. As may be appreciated, the actuation lever  90  and the spring levers  96  and  99  of the exemplary embodiment of  FIGS. 3 and 4  work in concert and together provide the switch actuator. 
     During installation of the door opening actuator  10 , the sash  90  must be pulled so that the actuator lever  90  is a first position indicated by the actuation lever  90  shown in dashed lines in  FIG. 3 . The sash is anchored and tensioned as desired. The spring levers  96 ,  99  in this position resiliently press the buttons  79  and  81  into their depressed position shown at  102 . 
     In one example, the switch  71  is normally closed when not pressed. However, in the embodiment of  FIGS. 3 and 4 , the initial position for operation of the door opening actuator  10  is with the button  71  pressed. Thus, during use, switch  71  is held in the open position. Therefore, when a fusible link breaks, the actuation lever is released and is biased into its normally closed position. Button  79  is disengaged by the actuation lever  90  and the spring lever  96  so that the first switch  71  moves into its closed condition. As may be appreciated, the series connection of the first pair of wires  57  from the first switch  71  to the first pair of terminals and the push button circuit  24  will actuate door  14  as though the push button  28  had been pressed when the circuit  24  is a normally closed circuit. Alternatively, a parallel connection of first pair of wires  57  from the first switch  71  to the first pair of terminals and the push button circuit  24  will actuate the door  14  as though the push button  28  had been pressed when the circuit  24  is a normally open circuit. Thus, if the door  14  is originally closed when a fusible link breaks, the door  14  will be caused to go up by the closure of switch  71  under the same protocol as for operation of the door by the push button  28 . At the same time, the second switch  73  is normally open when the button is not engaged so that during operation with the button  79  pressed, the second switch is held closed. When the fusible link breaks, the actuation lever  90  is released and the second switch is moved to the open condition. This may send a signal to the operator akin to that received when an obstruction is detected by the sensor  29 . Since the door  14  is closed or already going up, the protocol may do nothing to change the action by the operator as under similar conditions with an obstruction detected by the sensor  29 . Alternatively, the protocol may completely interrupt wiring to the sensor to prevent the door from closing. 
     As shown in  FIG. 2 , the second switch  73  may be connected in series by the second pair of wires  61  from the door opening actuator  10  with the pair of wires from the obstruction circuit  27 . This is advantageous because the obstruction circuit operates as a normally closed circuit and is opened when an obstruction is detected. Therefore, holding the second switch  73  in the closed condition absent a fire enables the second switch to function properly when placed in series with the obstruction circuit. In this configuration, it can be appreciated that as soon as a fusible link is broken, the emergency door opening actuator will open the circuit formed in series with the obstruction sensing circuit  27  and the door  14  cannot close. 
     In the case of the door  14  being already open, actuation of the door opening actuator  10  when a fusible link breaks will cause the first switch to close, which will start closing the door. However, the second switch will be opened causing the door  14  to either stop of reverse and go up in accordance with the protocol in the operator  15  for the case in which the door  14  is descending and an obstruction is sensed. Similarly, if the door  14  is stopped between a completely opened and a completely closed condition, then either the first switch will send the door  14  up or the second switch will send the door up in accordance with the existing protocols in the operator  15 . Once again, with the series circuit formed with the obstruction sensing circuit open, the door  14  cannot close. 
     The third switch  75  may be connected to the fifth and sixth terminals by the third set of wires  65  in systems  12  that have a protocol for connection with an alarm system. Depending on whether the configuration of the alarm system operates as normally closed or normally opened, the third set of wires  65  may be connected in series as shown or in parallel. The third pair of wires  65  may thus send a signal that actuates the alarm system when a fusible link breaks and the switch actuator is released. 
     The fourth switch  77  may be connected to a seventh and eighth terminal by a fourth pair of wires  69  as a fail safe measure for sending the door  14  up if the first and second switches  71  and  73  fail to cause the door  14  to go up, in a case of a burned switch or wires. Alternatively, the fourth switch may replace the function described above with regard to the first and second switches  71  and  73  by causing the door  14  to go up when a fusible link breaks and the fourth switch is actuated. A protocol may be provided in the operator to respond to such a signal and preferentially open the door  14  under such emergency conditions. 
     It is to be understood that while a specific example has been shown and described herein, the same function may be achieved by a different combination of parallel and/or series connections without departing from the spirit and scope of the invention. For example if the push button circuit  24  were to operate in a normally closed condition so that opening the circuit  24  actuates the door  14 , then a parallel connection of the first pair of wires would have to be replaced by a series connection. Similarly, the switches need not be initially held in a condition opposite from their at rest condition. The circuitry may be adjusted to accommodate such modifications. 
       FIG. 5  is a diagrammatic view of the operator  15  and the door opening actuator  10 . As shown, the terminal strip  21  may include first through eighth terminals, which may be connected to the first through the fourth switches  71 ,  73 ,  75 , and  77 . In this diagram, the switches are shown as separately housed switches that have respective buttons. A switch actuator  105  may be moved between an engaging and a non-engaging position as shown in solid and dashed lines. This switch actuator  105  may be a combination of levers  90 ,  96 , and  99 , or may be a single member. The switch actuator  105  may be coupled to one or more fusible links  33 . The switch actuator may also be coupled by the sash  30  to the anchor  36 . For engagement in a structural member of the building in which the door opening actuator is to be installed. 
     As indicated by the plurality of fusible links  33 , the plurality of guide rollers  31 , the sash may be routed to any location within the building, and may be used to selectively distribute fusible links throughout the building. For example, a first fusible link  33  may be located proximate to the operator  15 . A second fusible link may be located on an opposite side of a wall such as the drywall ceiling  45  for response to a fire or associated heat that may be temporarily isolated to a volume within the attic. Other locations in the attic may be monitored similarly by a long sash that may extend to remote positions in the attic as shown in  FIG. 1 . Thus, if any of the fusible links breaks, then the door opening actuator will be actuated and will in turn cause the operator  15  to raise the associated overhead door  14 . 
       FIG. 5  also include a timing device  108  that may be operably connected to the switches  71 ,  73 ,  75 , and  77 . This timing device may be desirable in some circumstances in order to delay the opening of the door  14 . For example, the timing device could delay causing actuation of the door for approximately five to ten minutes so that the fire may be isolated for the short period of time between notification of the fire department and their arrival. This may be beneficial for buildings that have an alarm system that automatically notifies the fire department. However, the safety issues of a need for egress will usually override any advantage that a timing device may provide. 
     The door raising actuator  10  may also include a backup power supply  112  that may be connected to the operator and/or time delay device  108 . The battery backup may include one or more batteries and may have sufficient power to raise the door completely and actuate any alarms. 
     Several advantages are provided by the present invention. Of greatest importance, an escape route may be provided by actuation of the door caused by the emergency door opening actuator  10  of the present invention. Furthermore, entry through the garage door is one of the second most preferred modes of entry for fire fighters attempting to enter a burning house. With the present invention, the garage door will be automatically opened. Therefore, entry therethrough may be facilitated and may become the preferred mode of entry. Other advantages of the present invention may include the fact that opening the garage in accordance with the present invention may draw the fire away from other parts of the home and into the garage by feeding oxygen to the fire at the garage door. 
     The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those of ordinary skill in the art to make and use the invention. However, those of ordinary skill in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the teachings above without departing from the spirit and scope of the forthcoming claims. For example, while the present invention has been shown and described as formed of micro-switches and relatively large switch actuators that engage the switches, analogous circuitry may be incorporated on a circuit board or as a microcircuit. Additionally, while the present invention has been shown and described with regard to opening an overhead door in an emergency, the same principles could be used for closing doors in case of emergencies. Doing this is desirable in some applications similar to fire door applications in which isolation of a fire is the goal. In this regard, the present invention has application in residential garage doors and commercial applications for both opening and closing overhead doors.