Patent Publication Number: US-2023149757-A1

Title: Ultra-high temperature fusible link

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/038,569, filed Sep. 30, 2020, which claims the benefit of and priority to U.S. Provisional Application No. 62/908,880, filed on Oct. 1, 2019, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Fire suppression systems are commonly used to protect an area and objects within the area from fire. Fire suppression systems can be activated manually or automatically in response to an indication that a fire is present nearby (e.g., an increase in ambient temperature beyond a predetermined threshold value, etc.). Once activated, fire suppression systems spread a fire suppression agent throughout the area. The fire suppressant agent then extinguishes or prevents the growth of the fire. 
     SUMMARY 
     One embodiment of the present disclosure relates to a fusible link assembly. The fusible link assembly including a first detection line, a second detection line, and a fusible link. The fusible link includes, a first substrate with a first end coupled to the first detection line, a second substrate with a first end coupled to the second detection line, and a solder layer directly bonded to a second end of the first substrate and a second end of the second substrate. The solder layer is configured to prevent separation of the first substrate and the second substrate until the solder layer reaches a temperature between 500° F.-575° F. 
     Another embodiment of the present disclosure relates to a fusible link. The fusible link includes, a first substrate, a second substrate, and a solder layer directly bonded to a first end of the first substrate and a first end of the second substrate. The solder layer is configured to prevent separation of the first substrate and the second substrate until the solder layer reaches a temperature between 500° F.-575° F. 
     This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an illustration of a fire suppression system according to an exemplary embodiment. 
         FIG.  2    is a perspective view of a fusible link according to an exemplary embodiment. 
         FIG.  3    is an illustration of the fusible link of  FIG.  2   . 
         FIG.  4    is a partial section view of the fusible link of  FIG.  3   . 
         FIG.  5    is a flowchart depicting a method of using a fusible link assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting. 
     Hazard areas (e.g., kitchens, vehicles, etc.) often place flammable materials (e.g., grease, oil, cloth, hydraulic fluid, etc.) in close proximity to hazards, such as engines with superheated components (e.g., combustion chamber, etc.), or cooking appliances that include heat sources (e.g., ovens, stoves, fryers, etc.). Because of this, hazard areas often experience fires, especially in the engine bay or near cooking appliances. Hazard areas are often outfitted with fire suppression systems to combat such fires. These fire suppression systems generally include nozzles that are configured to supply a fire suppressant agent (e.g., water, foam, powder, etc.) toward a hazard (e.g., one of the cooking appliances) in response to detection of a fire to suppress the fire. Detection components, such as fusible links, are implemented in the hazard areas to determine if a fire has ignited, as well as activate safety components (e.g., closure of a fire door, closing/opening of vents, dampers, etc.). 
     Fusible links generally include a pair of fusible link plates coupled with a solder. The solder in part determines the temperature rating for the fusible link that may be set forth by a safety or regulation agency or company such as, for example, Underwriters Laboratories (UL). Fusible links may be classified into Low (e.g., 125-130° F.), Ordinary (e.g., 135-170° F.), Intermediate (e.g., 175-225° F.), High (e.g., 250-300° F.), Extra high (e.g., 325-375° F.), Very extra high (e.g., 400-475° F.), and Ultra high (e.g., 500-575° F.) temperature classifications. Each temperature classification may also have a maximum ambient temperature set forth by UL or another organization, such as Low (90° F.), Ordinary (100° F.), Intermediate (150° F.), High (225° F.), Extra high (300° F.), Very extra high (375° F.), and Ultra high (475° F.). In the event of a fire in a hazard area, the ambient temperature will increase. Once the ambient temperature increases to a temperature within an activation temperature range for a fusible link, the fusible link decouples. Once the fusible link is decoupled, the fire suppression system receives an activation signal to release fire suppressant agent. 
     Fusible links or components thereof can include a plating and/or a coating. The plating can be a metal (e.g., gold alloy, silver alloy, nickel alloy, etc.) and facilitate stronger mechanical bonding of solder to the fusible link plates. The coating can be a non-metal or a metal-based material (e.g., wax, paint, etc.). The coating can prevent corrosion of the fusible link, which could cause malfunctions of the fusible link if corroded. For example, according to some UL standards the coating should resist cracking, flaking, slipping, or flowing when tested at the maximum temperature in which the assembly may be installed. The coating can also refer to a color code identifying a specific temperature rating (e.g., low, ordinary, intermediate, high, extra high, very extra high, ultra high, etc.) of the fusible link. 
     Fusible links may be required to pass various tests set forth by UL. These tests may test various properties of the fusible link which could cause failure of the fusible link in a fire suppression system, such as the response time of the fusible link, the durability when exposed to high temperatures below the maximum ambient temperature, and corrosive resistance. 
     Referring generally to the figures, fire suppression systems are configured for use in a hazard area (e.g., a kitchen, an engine, etc.). Fire suppression systems include elements that suppress fire within the hazard area. One or more nozzles are configured to release a fire suppressant agent on an element (e.g., a combustion chamber, a supercharger, a fryer, a stovetop, etc.). The nozzles are fluidly coupled to an agent tank, which is configured to contain a quantity of fire suppressant agent. A release assembly is coupled to the agent tank to facilitate the release of fire suppression agent from the agent tank via an actuator and a cartridge of expellant gas. The actuator is configured to facilitate the release of the expellant gas from the cartridge into the agent tank. 
     The fire suppression system includes a control system configured to facilitate activation (e.g., puncture of the cartridge, etc.) of the fire suppression system. The control system includes a controller configured to receive and transmit signals to various components of the fire suppression system. The signals can be received from one or more fire detection devices (e.g., fusible links, linear detection lines, thermal detectors, etc.), which are configured to sense if a fire has occurred within a coverage zone of the fire detection devices. Fusible links are rated for specific ranges of temperatures. Thermal properties of the materials used for the various components of the fusible link determine the specific temperature range for the fusible link. Therefore, certain materials are usable in certain applications of fusible links, for example, higher ambient temperatures within a hazard area may require higher temperature rated fusible links to prevent malfunctions of the fire suppression system. Specific paints, coatings, and solders are beneficial in ultra-high temperature rated fusible links. 
     Referring to  FIG.  1   , among others, a fire suppression system  10  is shown. The fire suppression system  10  can be configured to suppress a fire in a stationary application (e.g., a kitchen, etc.) or in a mobile application (e.g., a truck, etc.). The fire suppression system  10  can utilize various fire suppressant agents (e.g., foam, water, etc.) to suppress a fire. The fire suppression system  10  is configured to activate (e.g., release the fire suppressant agent, etc.) if a fire is detected. The fire suppression system  10  can be configured to release a large quantity of agent over a short duration of time. The fire suppression system  10  can be configured to release a larger quantity of agent over a first duration, then release a smaller quantity over a second longer duration to prevent the fire from reigniting. The fire suppression system  10  can be activated mechanically or electronically. 
     The fire suppression system  10  includes an agent tank  12 . The agent tank  12  defines an internal volume  14 , which contains a quantity of fire suppressant agent (e.g., foam, water, etc.). The agent tank  12  can be positioned in close proximity to a hazard area to facilitate rapid activation of the fire suppression system  10 . The agent tank  12  can be positioned remote of the hazard area to facilitate more accessibility to the agent tanks  12 . The agent tanks  12  are coupled to a release assembly  16 , which is configured to facilitate the release of fire suppressant agent from the agent tanks  12 . The release assembly  16  includes a cartridge  18  and an actuator  20  removably coupled to the agent tank  12 . The cartridge  18  defines an internal volume  22  configured to contain a quantity of release gas. The actuator  20  couples to the cartridge  18  and includes a mechanism  24  (e.g., a pin, a needle, a blade, etc.) configured to penetrate the internal volume  22  of the cartridge  18 . The release assembly  16  couples to a release piping  26 , which fluidly couples the internal volume  22  of the cartridge  18  to the internal volume  14  of the agent tank  12 , such that when the actuator  20  penetrates the internal volume  22  of the cartridge  18 , the release gas can flow from the cartridge  18  to the internal volume  14  of the agent tank  12 . 
     The fire suppression system  10  also includes distribution piping  28  (e.g., tubing, etc.) coupled to the agent tank  12 . The distribution piping  28  and the agent tank  12  can be removably coupled to facilitate removal of the agent tank  12  from the fire suppression system  10 . The distribution piping  28  can be configured to direct the fire suppression agent released from the agent tank  12  to one or more nozzles  30 . The nozzles  30  can be coupled to the distribution piping  28  at distal ends (e.g., ends open to an ambient environment, etc.) and configured to release the fire suppression agent into the ambient environment. The nozzles  30  are directed (e.g., aimed, etc.) such that the fire suppression agent, when released into the ambient environment, releases towards a hazard area (e.g., an area with a higher chance of fire, etc.) to suppress a fire within the hazard area. 
     The fire suppression system  10  can be configured to activate automatically and/or manually. The fire suppression system  10  is configured to activate manually, such that the fire suppression system  10  includes a manual activation device  32 . The manual activation device  32  may include a button  34 , a knob, a lever, a switch, or another type of user interface that is configured to receive an input from a user. The manual activation device  32  can be located in close proximity to the hazard area, or the manual activation device  32  can be located remote from the hazard area. The fire suppression system  10  includes at least one manual activation device  32  located in close proximity to the hazard area and at least one manual activation device  32  located remote from the hazard area. The fire suppression system  10  is configured to activate electronically, such that the fire suppression system  10  includes one or more thermal detectors  36 . The thermal detectors  36  can be located in close proximity to the hazard area, and configured to detect whether a fire has ignited within the hazard area. The fire suppression system  10  can include a controller  38  configured to receive signals (e.g., electrical, mechanical, pneumatic, etc.) from the thermal detectors  36  and/or the manual activation device  32  and send signals to the actuator  20 . The thermal detectors  36  and/or the manual activation device  32  are configured to send signals directly to the actuator  20 . 
     The controller  38  is configured to send and receive signals within the fire suppression system  10 . The controller  38  can be directly coupled to the manual activation device  32 , the actuator  20  of the release assembly  16 , and/or the thermal detectors  36 . The controller  38  includes a processor and a memory. The controller  38  may be configured to provide electrical activation signals to each of the actuators. The controller  38  is configured to electronically sense (e.g., with a strain gauge, with a switch, etc.) a tensile force. 
     The fire suppression system  10  includes a fusible link assembly  100 . The fusible link assembly  100  can be located in close proximity to the hazard area (e.g., above, adjacent, etc.). The fusible link assembly  100  can be configured to activate once an ambient temperature increases above a threshold maximum ambient temperature. 
     The fusible link assembly  100  includes a pair of tensile members (e.g., ropes, cables, rods, etc.), shown as detection lines  104 , each coupled to a fusible link  102  by fasteners, shown as S hooks  106 . A first S hook  106  couples to a first side of the fusible link  102  and a second S hook  106  couples to a second side of the fusible link  102 . The detection lines  104  extend longitudinally outward from the fusible link  102 . The detection lines  104  are held in tension such that the fusible link assembly  100  is held in tension. Elevated ambient temperatures cause separation of the fusible link  102 , reducing the tension on the detection lines  104  and acting as a signal to activate the fire suppression system  10 . The fire suppression system  10  can include a bracket, shown as cover  108  that extends around the detection lines  104 , preventing objects from coming into contact with and damaging the fusible link assembly  100 . 
     The detection lines  104  are routed such that the detection lines  104  can send an activation signal (e.g., a reduction in tensile force) to activate one or more fire suppression functions of the fire suppression system  10 . One or both of the detection lines  104  send activation signals directly to (e.g., are directly coupled to) the actuator  20  of the release assembly  16 . 
     The detection lines  104  are indirectly coupled to the actuator  20  of the fire suppression system  10  by the controller  38 . The controller  38  is a purely mechanical device that receives the tensile force from one or both of the detection lines  104  and applies forces on one or more of the actuators to control operation of the fire suppression system  10 . In response to receiving an activation signal (e.g., a decrease in tensile force) from the detection line  104 , the controller  38  may send an activation signal (e.g., a change in applied force) to one or more actuators to activate the fire suppression system  10 . The controller  38  may include one or more mechanical devices (e.g., winches, pulleys, gears, linkages, pressurized air tanks, levers, etc.) that facilitate the transfer, conversion (e.g., from a force to a torque, etc.), or production of mechanical energy by the controller  38 . The controller  38  is configured to receive the tensile force from one of the detection lines  104  and apply a tensile force to a separate detection line  104  coupled to each of the actuators. When the fusible link  102  activates, the controller  38  may receive the reduction in force (e.g., the activation signal) from the detection line  104  and change the force applied to each of the other detection lines  104 , thereby providing an activation signal to each of the actuators. The controller  38  is configured to puncture or otherwise open a container of pressurized gas in response to experiencing a decrease in the tensile force of the detection line  104 . The pressurized gas may pass through one or more conduits (e.g., hoses, pipes, etc.) to the actuators, such that an increase in pressure experienced by the actuators acts as an activation signal. 
     The fusible link assembly  100  is configured to activate a safety function of the fire suppression system  100 . The safety function can be a function separate of the release of fire suppressant agent onto a fire (e.g., opening or closing a door, a vent, a damper, etc.). By way of example, the fusible link assembly  100  can couple to a vent on a first end and an anchor on a second end. The anchor prevents the fusible link assembly  100  and the vent from moving while the fusible link assembly  100  is in a non-activated state. After activation of the fusible link assembly  100 , the vent may move freely (e.g., open, close, etc.) to open a flow path or close a flow path for air into or out of the hazard area. For example, the vent may open to facilitate venting of smoke out of a room, or the vent may close to lessen oxygen flow into a room. 
     Referring to  FIGS.  1 - 4   , the fusible link  102  is shown in greater detail. As described above, if the ambient temperature within the hazard area increases above a maximum temperature of the fusible link  102 , the fusible link  102  activates to release tension in the detection lines  104 . The fusible link  102  may be rated for various temperature ranges, such as Low (e.g., 125-130° F.), Ordinary (e.g., 135-170° F.), Intermediate (e.g., 175-225° F.), High (e.g., 250-300° F.), Extra high (e.g., 325-375° F.), Very extra high (e.g., 400-475° F.), and Ultra high (e.g., 500-575° F.). Fusible link  102  includes solder  112  (e.g., a thermally sensitive material, a solder layer, etc.) and fusible link plates  110  (e.g., substrates, etc.) configured to couple to the solder  112 , the S hooks  106 , and the detection lines  104 . The solder  112  is configured to fixedly couple the fusible link plates  110  and limit the movement of the fusible link plates  110  relative to each other. The solder  112  is further configured to activate (e.g., melt, etc.) when an ambient temperature increases to a temperature above an activation temperature (e.g., a melting temperature, etc.) of the solder  112 , to decouple the fusible link plates  110 . The fusible link plates  110  can include a plating, as described above, (e.g., gold alloy, silver alloy, nickel alloy, etc.) configured to facilitate stronger mechanical bonding of the solder  112  to the fusible link plates  110 . The fusible link  102  can also include a coating (e.g., paint, wax, etc.) applied to the soldered fusible link plates  110  configured to minimize corrosion of the fusible link  102 . 
     The fusible link plates  110  can be identical to facilitate easier manufacturing. The fusible link plates  110  can include a coupling aperture  114  (e.g., a hole, an opening, etc.) and a coupling protrusion  116 . The flexible link plates  110  can include more than one coupling aperture  114  and more than one coupling protrusion  116 . The coupling aperture  114  is configured to align with the coupling protrusion  116  in an opposing fusible link plate  110 . The fusible link plates  110  can include flanges  118  on a first end  120 , which define an aperture  122 , configured to accept the S hook  106  or another coupling device (e.g., fastener). The aperture  122  can be circular, as shown in  FIGS.  1 - 4   , however the aperture  122  can be any shape suitable for receiving the S hook  106  or other fastener. The flanges  118  are configured to minimize stress concentrations at the first end  120  of the fusible link plates  110 , which could otherwise result in malfunctions of the fusible link  102 . 
     The fusible link plates  110  can include a plating that plates a surface of the fusible link plates  110 . The plating can plate a portion (e.g., more than half of the surface area, etc.) of the fusible link plates  110  to minimize an amount of plating used during manufacturing. The plating can plate the entire surface of the fusible link plates  110  to minimize surface flaws, which can cause poor bonding of the solder  112  to the fusible link plates  110 . The plating can function as a bonding agent for the solder  112  to mechanically bond to the fusible link plates  110 . The plating can also function as a corrosive resistant surface. The plating can be plated on the fusible link plates  110  via electroplating. Some suitable materials for the plating can be gold alloy, silver alloy, nickel alloy, etc. The fusible link plates  110  can also include multiple layers of coating (e.g., a first layer of nickel alloy and a second layer of gold or silver alloy, etc.). 
     By way of example, a first fusible link plate  110  is coupled to a second fusible link plate  110  with solder  112 . The solder  112  is configured to mechanically bond with the first fusible link plate  110  and the second fusible link plate  110 , fixedly coupling the first fusible link plate  110  to the second fusible link plate  110 . The solder  112  may cover all or portions of the interfacing surfaces of fusible link plates  110 . On each fusible link plate  110 , the solder  112  may be provided at one or more of: between the coupling protrusion  116  and an end of the fusible link plate  110 , between the coupling protrusion  116  and the coupling aperture  114 , and between the coupling aperture  114  and the aperture  122 . The solder  112  is configured to fixedly couple the first fusible link plate  110  to the second fusible link plate  110  until the ambient temperature surrounding the solder  112  increases to a predetermined threshold temperature. Once the ambient temperature increases above the predetermined threshold temperature, the first fusible link plate  110  decouples from the second fusible link plate  110  due to the solder  112  transitioning from a solid state to a liquid state (or a semi-liquid state). The predetermined threshold temperature depends on the material properties of the solder  112 . 
     Suitable materials for a solder  112  with a predetermined threshold temperature threshold between 500-575° F. include high lead content thermally sensitive materials  112 . Solders such as, Lead-Indium solder alloy (e.g., 81% Pb and 19% In, etc.), Lead-Tin-Silver solder alloy (e.g., 88% Pb, 10% Sn, and 2% Ag, etc.), or Lead-Tin solder alloy (e.g., 90% Pb, and 10% Sn, etc.). Examples of specific solders are Indalloy 228, 150, and 159. Fusible links utilizing Indalloy 228 had an average operating temperature, when tested per UL33 section 10, of 553° F. Fusible links utilizing Indalloy 150 had an average operating temperature, when tested per UL33 section 10, of 509° F. Fusible links utilizing Indalloy 159 had an average operating temperature, when tested per UL33 section 10, of 563° F. 
     Fusible link  102  can include a coating (e.g., paint, etc.), which is utilized for corrosion protection, as well as marking of the fusible link  102 . The coating can cover the fusible link plates  110 , and/or the solder  112 . The paint resists removal (e.g., becoming chalky, flakey, etc.) after exposure to constant temperatures close to the maximum ambient temperature of the fusible link  102 , and resists melting or burning when exposed to these temperatures. Many conventional paints are not suitable for ultra high temperature fusible link applications. Suitable materials for paints able to withstand temperatures of 500-575° F. include silicone based paints (e.g., Temperkote 850, Thermalox 8200, etc.). 
     Referring to  FIG.  5   , a method  500  of using a fusible link assembly is illustrated. At  502 , a first detection line (e.g., the detection line  104 ) is coupled with a first end of a first substrate (e.g., the fusible link plate  110 ) of a fusible link  102 . At  504 , a second detection line (e.g., the detection line  104 ) is coupled with a first end of a second substrate (the fusible link plate  110 ) of the fusible link. At  506 , bonding a solder layer (e.g., the solder  112 ) to a second end of the first substrate and a second end of the second substrate. The solder layer is configured to prevent separation of the first substrate and the second substrate until the solder layer reaches a temperature between 500° F.-575°. The method  500  can further comprise coupling the first and second detection lines to an actuator  20  of a fire suppression system via a controller  38  and applying force on the actuator to control operation of the first suppression system. Further, once an ambient temperature increases above a predetermined threshold temperature, the fusible link is activated such that the first substrate decouples from the second substrate due to the solder layer transitioning from a solid state to a liquid state (e.g., melting). The decoupling of the first and second substrates decrease the force applied and generates an activation signal at the actuator, thus activating the fire suppression system. 
     As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims. 
     It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples). 
     The term “coupled,” as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. Such members may be coupled mechanically, electrically, and/or fluidly. 
     The term “or,” as used herein, is used in its inclusive sense (and not in its exclusive sense) so that when used to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is understood to convey that an element may be either X, Y, Z; X and Y; X and Z; Y and Z; or X, Y, and Z (i.e., any combination of X, Y, and Z). Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to each be present, unless otherwise indicated. 
     References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure. 
     It is important to note that the construction and arrangement of the fire suppression system as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. 
     Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. For example, the coating may be incorporated in the fusible link  102 . Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.