Patent Publication Number: US-9851121-B1

Title: Heat-actuated fire damper sealing apparatus

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to air handling equipment having dampers and damper sealing systems and, more particularly, to a heat-actuated fire damper sealing apparatus configured to close and lock a plurality of dampers automatically when a fire condition is detected. 
     In general, dampers are used to control the flow of air and may be used to regulate temperature and air flow to a room. Dampers allow for zone heating and cooling for the comfort of residents or workers. In addition, fire dampers may be positioned in ductwork as part of a fire control strategy. Dampers may be moved between open and closed positions manually, according to the setting of a thermostat, or as controlled by circuitry or programming. 
     Although presumably effective for their intended purposes, the existing devices and proposals do not detect a fire condition and then automatically actuate the mechanical closing of the dampers of a damper framework. Further, the prior art does not disclose an apparatus that provides a locking assembly that prevents a reverse rotation of a closing rod or reverse movement of a locking plate following a first operation after detection of the fire event. 
     Therefore, it would be desirable to have a heat-actuated fire damper sealing apparatus that actuates an axle to rotate and cause closure of a plurality of dampers when a fire condition is detected. Further, it would be desirable to have a heat-actuated fire damper sealing apparatus that prevents an unlocking of closed dampers even if the fire detection assembly and damper closure assembly are damaged or destroyed by fire. 
     SUMMARY OF THE INVENTION 
     A heat activated sealing apparatus according to the present invention is configured to close and lock a plurality of ventilation damper blades of a ventilation framework that are movable from an open configuration to a closed configuration when a fire event is detected. The sealing apparatus includes a fire detection assembly capable of detecting a fire condition. A damper closure assembly includes an axle having a proximal end in operative communication with the actuator of the fire detection assembly and a distal end operatively coupled to the plurality of dampers of the ventilation framework, the axle being selectively rotatable between a start configuration at which the plurality of ventilation dampers are at the open configuration and a deployed configuration at which the plurality of ventilation dampers are at the closed configuration. 
     The damper closure assembly includes a locking assembly slidably movable between an unlocked configuration allowing rotatable movement of the axle and a locked configuration not allowing rotatable movement of the axle. The locking assembly is movable to the locked configuration only when exposed to a predetermined amount of heat from the fire condition. 
     Therefore, a general object of this invention is to provide a heat-actuated fire damper sealing apparatus configured to close and lock a plurality of dampers automatically when a fire condition is detected. 
     Another object of this invention is to provide a heat-actuated fire damper sealing apparatus, as aforesaid, having a fire detection assembly for detecting a fire event, such as by sensing a sharp incline in temperature. 
     Still another object of this invention is to provide a heat-actuated fire damper sealing apparatus, as aforesaid, having a closure assembly in communication with the fire detection assembly and with the plurality of dampers and that is configured to mechanically close and lock the dampers. 
     Other objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a heat activated damper sealing apparatus according to a preferred embodiment of the present invention, illustrated with a plurality of dampers in an open configuration; 
         FIG. 2  is the sealing apparatus as in  FIG. 1 , illustrated with the plurality of dampers in closed configuration; 
         FIG. 3  is an exploded view of the sealing apparatus as in  FIG. 1 ; 
         FIG. 4  is an exploded view of the damper closure assembly as in  FIG. 3  illustrated with an axle extending through an upper portion of an axle opening of a locking plate; 
         FIG. 5  is an exploded view of the damper closure assembly as in  FIG. 3  illustrated with an axle extending through a lower portion of an axle opening of a locking plate; 
         FIG. 6 a    is a rear view of the damper closure assembly coupled to the fire detection assembly as in  FIG. 4 ; 
         FIG. 6 b    is an isolated view on an enlarged scale taken from  FIG. 6   a;    
         FIG. 7 a    is a rear view of the damper closure assembly coupled to the fire detection assembly as in  FIG. 5 ; 
         FIG. 7 b    is an isolated view on an enlarged scale taken from  FIG. 7   a;    
         FIG. 8  is a perspective view of the mounting plate and related components removed from the exploded view of  FIG. 4 ; 
         FIG. 9 a    is a perspective view of the mounting plate and related components removed from the exploded view of  FIG. 5 ; 
         FIG. 9 b    is an isolated view on an enlarged scale taken from  FIG. 7   a;    
         FIG. 10 a    is a front view of the closure assembly as in  FIG. 8 ; 
         FIG. 10 b    is a sectional view taken along line  10 - 10   b  of  FIG. 10   a;    
         FIG. 10 c    is an isolated view on an enlarged scale taken from  FIG. 10   b;    
         FIG. 11 a    is a front view of the closure assembly as in  FIG. 9   a;    
         FIG. 11 b    is a sectional view taken along line  11 - 11   b  of  FIG. 11   a;    
         FIG. 11 c    is an isolated view on an enlarged scale taken from  FIG. 11   b;    
         FIG. 12 a    is a front view of the closure assembly as in  FIG. 9 a   , illustrated when the springs are urging the locking plate partially upwardly; 
         FIG. 12 b    is a sectional view taken along line  12 - 12   b  of  FIG. 12 a   ; and 
         FIG. 12 c    is an isolated view on an enlarged scale taken from  FIG. 12 b   ; and 
         FIG. 13  is an exploded view of the sealing apparatus as in  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A heat activated damper sealing apparatus according to a preferred embodiment of the present invention will now be described in detail with reference to  FIGS. 1 to 13  of the accompanying drawings. The sealing apparatus  10  includes a fire detection assembly  20  for detecting a fire condition, a damper closure assembly  30  in communication with a framework  12  of dampers and that includes an axle  32  and a locking assembly  40 . 
     A framework  12  having a plurality of dampers  14  may be positioned near the cabin of a custom boat, yacht, or the like and is useful for selective ventilation. The dampers  14  may be selectively opened or closed by a user according to his preference or may be closed and locked automatically upon detection of a fire condition as will be described below. It is understood that the plurality of dampers  14  are all interconnected, such as with rods, rack and pinion and gear components, or other suitable linkages. The linkage for opening or closing the dampers may be purely mechanical or, in an embodiment, be remotely controlled such as by radio signals. 
     The fire detection assembly  20  may include a detection housing  22  containing circuitry, electronic components, or even a processor (not shown). A temperature probe may extend away from the detection housing  22  that is configured to detect an ambient temperature indicative of a fire condition. In other embodiments (not shown), the fire detection assembly may include other means for detecting fire, such as a smoke detector, carbon monoxide detector, or a combination of all three types of detection means. The fire detection assembly  20  may include an electrical cord  26  in communication with an AC or battery power source. 
     The damper closure assembly  30  includes an actuator  28  in electrical communication with the fire detection assembly  20  and is configured to be energized when the fire detection assembly  20  detects a fire condition. The damper closure assembly  30  is configured to close a plurality of dampers  14  arranged in a damper framework  12  when a fire condition is detected. The actuator  28  may include a motor (not shown) in electrical communication with the power source as described above. Again, the actuator  28  is energized when the fire detection assembly  20  (i.e. temperature probe) detects a fire condition. 
     The damper closure assembly  30  includes an axle  32  having an elongate configuration and, in an embodiment, having a hexagonal or other irregular shaped configuration for reasons that will be discussed later. The axle  32  includes a proximal end  34  operatively coupled to the actuator  28  of the fire detection assembly  20  and a distal end  36  operatively coupled to the framework  12 . When the actuator  28  is energized, the axle  32  is configured to rotate between a start configuration at which the plurality of dampers  14  is at an open configuration ( FIG. 1 ) and a deployed configuration at which the plurality of dampers  14  is at a closed configuration ( FIG. 2 ). 
     The damper closure assembly  30  includes a locking assembly  40  that is slidably movable between an unlocked configuration allowing rotatable movement of the axle  32  and an unlocked configuration not allowing movement of the axle  32 . The locking assembly  40  is only movable to the locked configuration (preventing movement of the axle) once a fire condition has been detected and the axle  32  has been actuated to rotate and close the dampers  14  of the framework  12 . 
     Now, more particularly, the locking assembly  40  may include a mounting plate  38  having a planar configuration that defines an aperture  39  proximate and adjacent an upper edge thereof, the aperture  39  being configured to receive the axle  32  therethrough. A locking plate  42  may be positioned adjacent the mounting plate  38  and defines an axle opening  44  aligned with the aperture  39  such that the axle  32  is configured to extend through the aperture  39  and axle opening  44 . The axle opening  44  includes an upper section  46  having dimensions and a configuration that allows the axle  32  to rotate freely as described above and a lower section  48  that does not allow rotation of the axle  32 . In other words, the axle  32  is captured and locked by the lower section  48 . The axle  32  is especially prevented from movement when the axle has a hexagonal or other non-cylindrical configuration. 
     The locking assembly  40  further includes at least one tension spring  50  (and preferably a pair of spaced apart springs as illustrated in the drawings) having a first end  52  coupled to the mounting plate  38  adjacent the upper edge  42   a  and having a second end  54  coupled to the locking plate  42 . The spring  50  (or springs) is normally biased to urge the locking plate  42  upwardly toward the first end of the spring  50  but is normally prevented from doing so by the second end attachment to the mounting plate  38 . But when allowed to be urged upwardly, as will be described below, the lower section  48  is able to capture the axle  32  therein so as to prevent further rotation of the axle  32 . 
     Further, the locking assembly  40  includes a locking flange  56  having an upper portion  57  coupled to the locking plate  42  and a lower portion  58  coupled to the mounting plate  38 , the upper and lower portions being connected together with a temperature sensitive fastener, such as solder, that is severed (such as by melting) when exposed to a predetermined degree of heat. Accordingly, the spring  50  is prevented from urging the locking plate  42  upwardly into locking engagement with the axle  32  so long as the locking flange  56  is not severed. 
     The spring  50  is configured to pull the locking plate  42  upwardly and into engagement with the axle  32  and, as described above, is permitted to do this once the link (locking fastener  59 ) between the upper portion  57  and lower portion  58  of the locking plate  42  is severed, such as by the melting of a soldered connection. When urged upwardly, the lower section  48  of the locking plate  42  engages the axle in a tight friction fit or enveloped configuration that prevent any further rotation of the axle  32 . The result of this action is that once the axle  32  has rotated so as to close the plurality of dampers  14  upon detection of a fire condition and heat from the fire condition causes a melting of the temperature sensitive fastener  59 , the locking plate  42  is pulled upward to engage the axle  32  and prevent the dampers from being reopened. 
     In a related aspect, a pair of laterally spaced apart guide members  60  is configured to receive and guide the locking plate  42  when moving upwardly as described above. Each guide member  60  is mounted to the mounting plate  38  and oriented vertically. Further, each guide member  60  has a linear configuration that defines an inwardly open channel configured to receive a respective side edge  42   b  of the locking plate  42  therein so that the locking plate  42  can move slidably therealong when being urged upwardly. 
     The locking assembly  40  also includes means for preventing the locking plate  42  from sliding or moving downwardly after it has first been urged upwardly by operation of the spring  50 . In other words, once the axle  32  is prevented from rotating by engagement by the lower section  48  of the locking plate  42 , there is an additional structure to prevent a relaxation of this engagement. More particularly, a stop member  62  (and, preferably, a pair of laterally spaced apart stop members) is coupled to the mounting plate  38  at a position downwardly displaced from the upper edge of the mounting plate  38  ( FIG. 4 ). The stop member  62  extends upwardly and outwardly. When the locking plate  42  is urged upwardly by contraction of the spring  50  as described above, the stop member  62  serves as a ramp over which the locking plate  42  is allowed to move. But, then, once a lower edge of the locking plate  42  moves above the stop member  62 , the stop member  62  acts as a shelf that prevents a downward movement of the locking plate  42  ( FIG. 9 b   ). 
     In use, the heat activated sealing apparatus  10  may be installed in a boat in proximity to and in communication with a framework  12  having a plurality of ventilation dampers  14 . It is understood that it is desirable, upon sensing a fire condition, to close the dampers so as to maintain clear air within a cabin portion of the boat or simply to decrease or eliminate a flow of air to feed the flames. Accordingly, when the fire detection assembly  20  detects a fire event, such as via a temperature probe or smoke detector, the actuator  28  is energized to cause rotation of the axle  32 , the axle  32  being operatively coupled to the dampers  14  of the framework  12 . 
     The dampers  14  may thereby be moved to a closed or sealed configuration. Then, when the heat of the fire condition reaches a sufficient level, the soldered fastener  59  of the locking flange  56  will melt so as to sever the lower portion  58  from the upper portion  57 . As described above, this enables the spring  50  to contract and urge the locking plate  42  upwardly—the lower section  48  of the axle opening  44  engaging and preventing further rotation (particularly preventing a reverse or opening type movement) of the axle  32 . As a result, the dampers are locked in a sealed and closed configuration—even if the closure assembly itself becomes heavily damaged by the fire condition. 
     It is understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.