Concealed sprinkler

More than one reissue application of U.S. Pat. No. 9,931,528 has been filed. This application is a continuation reissue of U.S. patent application Ser. No. 16/791,463, filed Feb. 14, 2020, which is an application for reissue of U.S. Pat. No. 9,931,528.This application isalso an application for reissue of U.S. Pat. No. 9,931,528, filed as U.S. patent application Ser. No. 14/922,961 on Oct. 26, 2015, which is aContinuation Application of U.S. patent application Ser. No. 14/087,712 filed Nov. 22, 2013 which is a Continuation Application of U.S. patent application Ser. No. 12/515,113 filed Dec. 3, 2009, (now U.S. Pat. No. 8,646,539 issued Feb. 25, 2014) which is a 35 U.S.C. 371 application of International Application No. PCT/US2007/085820, filed Nov. 28, 2007, which claims the benefit of priority to U.S. Provisional Patent Application No. 60/861,239, filed Nov. 28, 2006, each of which is incorporated by reference in their entirety.

The present invention relates generally to fire protection devices and more specifically to concealed fire protection sprinklers used preferably, for example, in institutional or commercial applications or alternatively in a residential setting.

Concealed-type fire protection sprinklers, which discharge a fire fighting fluid such as a water, gas or other chemical agent, can be designed to protect a variety of occupancies, both commercial and residential. In addition, the concealed-type sprinkler can be mounted in a pendant style configuration from a ceiling system or alternatively, the sprinkler can be configured as a sidewall sprinkler for mounting along a wall surface. Generally, the concealing feature of these sprinklers obscures the internal components from view. Thus, a concealed-type sprinkler is useful in residential occupancies for at least aesthetic reasons. One type of commercial occupancy in which a concealed-type sprinkler is employed is an institutional occupancy which includes, for example, correctional, detention, and mental health care facilities. Concealed-type sprinklers for institutional applications are preferably configured to have a tamper resistant thermally sensitive release mechanism to reduce the opportunity for occupants to injure themselves or others with the internal components of the sprinkler.

Industry accepted design criteria exists to minimize the hazard that concealed-type sprinklers may pose. For example, design criteria provides that an concealed sprinkler should be configured with a thermally sensitive trigger or release mechanism that can break away from the body of the sprinkler when a load of eighty pounds or more is suspended from the mechanism. Such criteria minimizes that the potential for someone to use the sprinkler as a device from which to hang themselves or others. Some known concealed sprinklers use a cover to conceal the internal components of the sprinkler in order to prevent unauthorized tampering with the sprinkler and its components. For example, U.S. Pat. No. 6,152,236 is directed to a combined trigger and concealing device for a sprinkler head to conceal components contained within the interior of the sprinkler body. The body and concealing device are further shown disposed within the recess of an escutcheon. The circular concealing device includes two overlapping fusible plates joined by a fusible bonding material which fails in the presence of a sufficient level of heat. In order to conceal the interior of the sprinkler body and provide a pathway for heat transfer to reach the interior of the concealing device, the concealing device is located a preselected distance below the bottom of the sprinkler body and a preselected radial distance within a boundary of the interior of the body. The concealing device therefore defines an annulus or gap between the device and the sprinkler body which is as much as 1/16 inches wide and ⅛ inch high. The concealing device also acts as a component of a trigger device by maintaining a pair of actuating pins in a biased position to hold an adjustment plate in place for supporting a closure member. The concealing device includes a pair of apertures disposed about a central opening to engage the actuating pins. The central opening provides access to an adjustment screw which applies a sealing pressure on the closure member.

It is believed that in one known sprinkler that uses a pair of actuating pins and a concealing device spaced from the bottom of the sprinkler, the gap between the concealing device and the sprinkler body provides access in which a wire or string can be threaded about the actuating pins to hold their relative positions. With the pins held in place, the concealing device can be removed without actuating the sprinkler thereby providing unauthorized access to the internal components of the sprinkler. Other known sprinklers having a cover engaged with a component internal to the sprinkler body in order to conceal the body interior of the sprinkler body are shown and described in U.S. Pat. Nos. 3,783,947, 6,520,865, and 6,367,559. Each of the these patents describe a cover or fusible plate assembly for a sprinkler body that includes a central opening for a tool or other object to access the interior of the body and adjust an internal component. In addition, each of the covers are shown as being within the perimeter of the interior of the sprinkler body and flush with or below the opening at the bottom of the sprinkler body.

Another concealed sprinkler is shown and described in U.S. Pat. No. 4,596,289 in which a cover member and valve closure means completely conceals the interior of the sprinkler body. However, the cover device is not completely supported in place by the sprinkler body or its internal components but instead engages a separate housing surrounding the body to support the outer tabs or projections of the cover.

The present invention is directed to a sprinkler having a trigger assembly that includes a cover plate assembly. The cover plate assembly is preferably configured to be disposed about the discharge end of a sprinkler body so as to minimize the pathways and access points to the internal components of the sprinkler. The cover plate assembly is preferably configured to engage the sprinkler body or its internal components to further present a substantially continuous surface area without designed access openings to the interior of the sprinkler. Accordingly, the cover plate assembly preferably provides means for sealing an internal chamber of the sprinkler body so as to prevent or substantially minimize unauthorized tampering with the sprinkler and its internal components. With the cover plate assembly preferably incorporated into the trigger assembly, the cover plate assembly preferably actuates the sprinkler upon being removed, dislocated or separated from its position about the discharge end of the sprinkler body. The cover plate assembly is further preferably configured to have a break-away connection with the sprinkler body, so as to separate from the sprinkler under the weight of a hanging load of eighty pounds or more. More preferably, the sprinkler body and cover plate assembly are located within a recess or housing of a surrounding escutcheon which can facilitate mounting the sprinkler and further seal off access to the internal chamber of the sprinkler body and the components contained therein.

One preferred embodiment of the sprinkler includes a body having a proximal portion and a distal portion. The body defines an internal passageway having an inlet and an outlet extending along a longitudinal axis. The distal portion includes an annular wall having an outer surface and an inner surface to further define a chamber distal of the outlet and in communication with the passageway. A portion of the annular wall further defines a distal opening at the distal end of the sprinkler body in communication with the chamber. The sprinkler further includes a deflector assembly coupled to the body. The deflector assembly preferably has a deflector plate disposed within the chamber, and the deflector plate has a first position distal of the outlet and a second position distal of the first position. In addition, the sprinkler has a closure assembly including a closure element engaged with the deflector plate such that when the deflector plate is in the first position the closure element is disposed within the outlet of the passageway. The preferred sprinkler also includes a trigger assembly having a thermally rated cover plate assembly and a lever assembly engaged with an inner surface of the annular wall to support the deflector assembly in the first position. The plate assembly preferably includes at least a first plate member including a lip portion. The plate assembly is further preferably engaged with the lever assembly such that the lip portion substantially circumscribes the portion of the annular wall defining the distal opening. The lip portion is further preferably axially spaced from another portion of the distal edge so as to define a gap height therebetween. Disposed between the distal edge and the lip portion is more preferably disposed a ring member for further sealing off access to the annular channel. The ring member is preferably made from a polymer material that can serve as an insulator between the cover plate assembly and the sprinkler body so as to improve the thermal responsiveness of the cover plate assembly. Even more preferably, the ring member is configured to center the cover plate assembly about the sprinkler body and further maintain the planar surface of the cover plate assembly substantially perpendicular to the longitudinal axis of the sprinkler body.

Another preferred embodiment of the sprinkler provides a body having a proximal portion and a distal portion. The body defines an internal passageway having an inlet and an outlet extending along a longitudinal axis, and the distal portion includes an annular wall having an outer surface and an inner surface to further define a chamber distal of the outlet and in communication with the passageway. A first portion of the annular wall preferably defines a distal opening at the distal end of the sprinkler body in communication with the chamber and a second portion of the annular wall preferably defines a shelf along the inner surface proximal of the distal opening. The sprinkler preferably further includes a deflector assembly coupled to the body. The body preferably has a deflector plate disposed within the chamber. The deflector plate preferably has a first position distal of the outlet and a second position distal of the first position. The preferred sprinkler further includes a closure assembly having a closure element engaged with the deflector plate such that when the deflector plate is in the first position, the closure element is disposed within the outlet of the passageway. The sprinkler further has a trigger assembly that preferably includes a lever assembly having a first end and a second end to respectively engage the shelf and a bridge element to support the deflector in the first position. A thermally rated plate assembly is preferably provided having at least a first plate member including a lip portion framing the first plate member. The lip portion substantially circumscribes the portion of the annular wall defining the distal opening.

Yet another preferred embodiment of the sprinkler provides a body extending along a longitudinal axis having a proximal portion and an enlarged distal portion, the distal portion including an annular wall having a proximal edge and a distal edge with an outer and an inner surface extending therebetween to define a chamber for housing a deflector assembly. A portion of the distal edge forms an opening at the distal end of the body in communication with the chamber. A cover plate is also provided, the cover plate preferably has a lip portion, the cover plate disposed beneath the body so as to substantially cover the distal opening, and the lip portion overlaps a portion of the distal edge forming the opening. The sprinkler further includes a housing having an inner surface defining a receptacle with a central through hole. A portion of the inner surface of the housing preferably engages the proximal edge of the annular wall so as to substantially enclose the chamber. Preferably, the housing is an escutcheon for surrounding the sprinkler body and flush mounting to a ceiling or wall. The body preferably extends through the through hole such that the enlarged distal portion is preferably seated within the receptacle, and an annular channel or gap is further preferably defined between the annular wall and the inner surface of the housing.

Another preferred embodiment of the sprinkler includes a body having a proximal portion defining an opening and a distal portion defining an outlet. The body defines an internal passageway between the inlet and the outlet to further define a first diameter. The distal portion of the body preferably includes an annular wall having an outer surface and an inner surface to further define a chamber distal of the outlet. The chamber preferably defines a second diameter greater than the first diameter. The preferred sprinkler also includes a deflector assembly having a deflector plate distal of the outlet disposed within the chamber. In addition, a closure assembly is included preferably having a closure element, a bridge assembly engaged with the closure element, a thermally responsive plate assembly, and at least one lever member having a first end engaged with the plate assembly and second end engaged with the distal portion of the body so as to engage the bridge assembly such that the closure element is disposed adjacent the outlet of the body to maintain a static fluid pressure up to about 500 pounds per square inch (psi).

Another sprinkler according to the present invention preferably includes a sprinkler body, the sprinkler body having a proximal portion including an proximal opening and a distal portion including an outlet. The body defines an internal passageway between the inlet and the outlet along a longitudinal axis, and the distal portion includes a chamber and a deflector assembly disposed within the chamber. The chamber further defines a distal opening. The sprinkler further preferably includes a thermally rated trigger assembly having a lever assembly and means for preventing access to the chamber.

In yet another preferred embodiment, a sprinkler preferably includes a sprinkler body having a proximal portion including an proximal opening and a distal portion including an outlet. The body further defines an internal passageway between the inlet and the outlet along a longitudinal axis, and the distal portion preferably includes a chamber defining a distal opening. A deflector assembly is preferably disposed within the chamber. A thermally rated trigger assembly preferably includes a lever assembly and a cover plate assembly disposed about the distal opening so as to substantially enclose the chamber. The cover plate assembly preferably engages the lever assembly to define a surface substantially perpendicular to the longitudinal axis, the surface defining a surface profile including a gap in communication with the chamber having a maximum gap width no greater than about 0.005 inches (0.127 millimeters).

Shown inis a first illustrative embodiment of a preferred sprinkler. The sprinkleris preferably configured as a concealed-type sprinkler. The sprinklercan be configured for commercial applications, including institutional applications as well as other commercial applications as defined by the requirements of Underwriters Laboratories, Inc. (“UL”) Standard 199 (2005), entitled, “Automatic Sprinklers for Fire-Protection Service,” (“UL Standard 199 (2005)”) which is incorporated by reference in its entirety. Further, in the alternative, the sprinklercan be configured for residential applications as defined by the requirements of UL Standard 1626 (2004), entitled “Residential Sprinklers for Fire Protection Service,” each of which is further defined by the applicable installation requirements of National Fire Protection Association (NFPA) Standards: NFPA-13 (2007) entitled, “Standards for the Installation of Sprinkler Systems”; NFPA-13D (2007) entitled, “Standards for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Mobile Homes; and NFPA-13R (2007) entitled, “Standards for the Installation of Sprinkler Systems In Residential Occupancies up to and Including Four Stories in Height.” The sprinklercan be configured for pendant style mounting with a pendant style deflector as shown, for example, in, or alternatively, the sprinklercan be configured for sidewall or substantially horizontal mounting with a sidewall deflector as shown, for example, in. The sprinklergenerally includes a body, a deflector assembly, and a cover plate assembly. The sprinkleris further preferably disposed within a mounting elementfor mounting to a ceiling structure such as, for example, a ceiling tile, dry wall ceiling or other structure forming the mounting surface. The mounting elementis preferably an escutcheonhaving a proximal end face for engaging the ceiling construct. The mounting elementpreferably tapers from the proximal end face to distal end face which is preferably located proximate to and more preferably substantially flush with a distal end of the body.

The sprinkler bodyhas a proximal portionand a distal portion. The outer surface of the proximal portionpreferably includes a threaded end fitting for coupling the sprinklerto a branch line of a sprinkler system containing a fire fighting fluid, for example, a liquid such as water, a pressurized gas such as compressed air, or a combination thereof, such as a foam. An inner surface portion of the bodyfurther defines an internal passagewayextending between an inletand an outletalong a longitudinal axis A-A. The inletis preferably in communication with tapering portiona of the passageway. The tapering passagewayis further preferably in communication with a portionb having a constant diameter and terminating at the outlet. The passageway, inletand outletfurther preferably define a sprinkler constant or K-factor ranging from about 3 gallons per minute per pounds per square inch raised to the one-half power (gpm/(psi))to about 5.8 (gpm/(psi))and is preferably about 5.6 (gpm/(psi)).

The distal portionpreferably includes an annular wallhaving a proximal edgecontiguous and more preferably integral with the proximal portion. The annular wallincludes an outer surfaceand an inner surfaceto further define a chamberdistal of the outlet. The bodyis preferably constructed such that the chamberis in communication with the passageway. The annular wallfurther includes a distal edgedefining a distal openingpreferably at the distal end of the bodyin communication with the chamber. The annular wallpreferably defines a first wall thickness, and the distal edge of the annular walldefines a wall thickness that is preferably less than the first wall thickness. The sprinkler bodygenerally defines substantially circular cross-sections in a plane perpendicular to the longitudinal axis A-A; however, it should be understood that the bodycan define other geometrical cross-sections such as, for example, oval or rectangular provide the bodycan deliver the desired flow and pressure of fluid.

The chamberis preferably configured for housing internal components of the sprinkler. More specifically, the chamberis preferably configured for housing the deflector assemblyand a closure element. The deflector assemblyis coupled to the bodyand is more preferably suspended in a telescoping manner from the proximal edge. More specifically, the proximal edgepreferably includes a pair of through holesa,b in communication with the chamber. The deflector assemblypreferably includes a pair of armsa,b engaged in the through holesa,b. The armsa,b each preferably include an enlarged proximal endfor engaging the proximal edgeof the annular wallso as to limit the distal and axial travel of the armsa,b in the through holesa,b. The proximal edgecan include additional openings to provide space for housing additional components within the chamber, for example, the proximal edgecan include two substantially semi-circular openings disposed about the proximal portionof the body. The additional openings can further provide a sprinkler assembler/installer access or view to the chamber.

Coupled to the distal endof each arma,b of the deflector assemblyis a deflector plate. The armsa,b preferably locate the deflector plateat a first position within the chamberdistally adjacent the outlet. The deflector platefurther preferably includes a central hole with a closure element or assemblyengaged therein. With the deflector platelocated at its first position, the closure elementis preferably located in the outlet of the passagewayto prevent the flow of a fluid (liquid or gas) from the outlet of the passagewayb. The closure elementpreferably includes a closure buttonhaving a preferably frustroconical tip with a partial bore. The partial boreis further preferably threaded for engagement with a tool used in the assembly of the sprinkler. Disposed about the frustroconical tip and engaged with a flangeof the closure buttonis a biasing elementto bias the closure assemblyin the direction of the distal opening. Preferably, the biasing elementincludes a Belleville spring disc having a spring force ranging from about 50 lbs. (222 Newtons) to about 120 lbs. (534 Newtons). With the closure elementin its sealing position, the frustroconical tip is preferably disposed within the passagewayand the biasing elementengages a preferably counter sunk surface forming the outletto the distal portionb of the passageway.

The axial travel of the armsa,b locates the deflector plateto at least a second position distal of its first position and preferably distal of the distal opening. With the deflector plate in its second position, the closure elementis preferably spaced from the outletso as to permit any fluid (liquid or gas) supplied to the bodyof the sprinklerto discharge from the outlet. Liquid discharged from the outletcan impact the axially displaced deflector platefor distribution about an area beneath the sprinkler. To facilitate a distribution of fire fighting fluid in an area being protected by the sprinkler, the deflector plate can include a pattern of closed or open ended slits, slots, through holes, openings, cut-outs or any combination thereof to satisfy any one of a vertical or horizontal fluid distribution test. Preferably the sprinkler bodyand deflector assemblycan be configured for standard coverage or extended coverage as defined by, for example, NFPA-13 (2007). The deflector plateis preferably a pendant style deflector plate as generally shown for example in.

The sprinkleris preferably a thermally actuated sprinkler so as to permit the passage of fluid from the outletin the presence of a sufficient amount of heat. Accordingly, the sprinklerincludes a trigger assembly. The trigger assemblypreferably includes a bridge elementand a lever assembly. The bridge elementpreferably includes a surface for supporting the deflector assemblyin its first position and the closure elementin its sealed position engaged with the outlet. More preferably, the bridge elementincludes a substantially planar upper surface to engage a portion of the closure elementwhich is preferably fixed within the central through hole of the deflector plate.

To locate the deflector assemblyin the first position and the closure element in the sealed position, the bridge elementis appropriately axially located within the chamber. Accordingly the lever assembly, by a preferably pivoted engagement with the inner surfaceof the annular wall, is configured to support the bridge elementin the desired location within the chamber. In one preferred embodiment, the lever assemblyincludes a pair of lever membersa,b diametrically disposed about the central axis A-A. The lever membersa,b preferably include one end for engaging the inner surfaceand another end for engaging the cover plate assembly. To facilitate the pivoted engagement between the annular walland the leversa,b, the inner surfacepreferably defines an annular shelf, and the engaging end of the lever membera,b preferably includes a flat for frictional engagement with the shelf. The engagement of the lever membersa,b with the cover plate assemblypreferably angle the lever membera,b relative to one another to form a frame for directly and indirectly supporting the bridge element, closure elementand deflector assembly.

To support itself about the lever membersa,b, the bridge elementis preferably configured to define a channelto receive the end portion of the lever membera,b so as to be straddled about the diametrically opposed ends of the lever members. Accordingly, the bridge elementis preferably trenched, grooved, and/or bracketed to resemble a U-shaped in cross-section. Alternatively, the bridge element can be a substantially single planar member for planar contact engagement with the components of the deflector and lever assemblies,. Where the material defining the cross-section has an aspect ratio equivalent to the material height or thickness over its width or length, the ratio is substantially less than one so as to define a small volume and minimize the space requirements of the bridge elementwithin the chamber. The bridge elementcan define a length so as to bridge the lever membersa,b at a location that locates the deflector assemblyin its first position and further locates the closure elementin its sealing position. More specifically, the length of the bridge element defines the point of contact on the lever membersa,b for transferring the load of biasing elementand further transferring any applied static fluid load in the passagewayto the trigger assembly. Upon actuation of the sprinkler, the lever membersa,b preferably pivot about the points of engagement with the shelfto axially displace the bridge elementso as to permit the axial translation of the deflector assemblyand the closure element.

The angular relation of the lever membersa,b relative to one another or another reference line, such as the longitudinal axis A-A of the sprinkler, is preferably defined by the engagement of lever membersa,b with the cover plate assembly. Preferably, the lever membersa,b define in between an included angle of about 136 degrees (136°) and accordingly each lever member defines an angle β of about sixty-eight degrees (68°) with the respect to the longitudinal axis A-A as seen, for example, in. However, any suitable angle can be formed between the lever members provided the lever membersa,b can support the cover plate assemblyand the closure element. The cover plate assemblyis also configured to provide means for concealing the components of the sprinklercontainer within the chambersuch as, for example, the deflector plateor the lever membersa,b. The cover plate assemblypreferably includes a first plate memberand a second plate membercoupled to the first plate member. The first plate memberpreferably includes a substantially planar surface portion that is sized so as to substantially cover the distal openingof the body. An out of plane, raised or lip portionof the first plate memberis contiguous and more preferably integral with the planar surface portion. The raised or lip portionpreferably defines a substantially circular perimeter of the plate member. Alternatively, the lip portioncan define a perimeter of an alternate geometry such as, for example, oval, rectangular or polygonal.

Preferably formed between the distal edgeand the remainder of the annular wallis a step transition or shoulder. Preferably spaced distally from the shoulder is the lip portionto define an axial space having a height h in between as seen, for example, in. Referring back to, the lip portionfurther has a diameter of a sufficient length so as to further define a circumference larger than the circumference of the distal edgeof the annular wallforming the distal opening. Thus, where the engagement of the lever membersa,b with the cover plate assemblylocates the first plate memberdistally adjacent the distal opening of the body, the lip portionpreferably overlaps and circumscribes the distal edge. The overlap of the lip portionprovides a parallel wall in combination with the distal edgeof the annular wallto further limit radial access to the chamber. More preferably, the lip portionpresents a continuous outer surface to circumscribe the distal edgeof the body. Alternatively, the lip portionmay include periodic gaps or slots of a sufficient frequency to define the lip portion and prevent radial access to the chamber. Accordingly, the preferred embodiment of the first plate memberand the cover plate assemblyfurther enhances the concealed nature of the sprinklerby further limiting access to the chamber. To fill in or otherwise minimize the axial space h in between the shoulder of the annular walland the lip portion, a ringis preferably disposed within the axial space, as more specifically shown inthereby further eliminating a void into which a foreign object may be inserted to tamper with the sprinkler. Shown inis an illustrative embodiment of the ring. The ringcan act as a flat washer orienting the cover plate assemblysuch that the surface of the assembly concealing the chamberis substantially orthogonal to the longitudinal axis A-A. The ringis preferably made of a polymer material such as, for example, Teflon, polyethylene, polypropylene or more preferably nylon. The polymer preferably provides the ringwith insulation properties such that the ringcan behave as an insulator between the cover plate assemblyand the remainder of the sprinkler. By substantially insulating the cover plate assembly, heat from a fire event can impact the cover plate assemblywithout significant heat transfer to other portions of the sprinklerthereby facilitating appropriate thermal response by the cover plate assemblyin the presence of a heat or fire event.

To further enhance the concealing function of the lip portionand the first and second plate members,of the cover plate assembly, the distal edgecan include additional features that cooperate with the lip portionand deter tampering with the internal components of the sprinklerhoused within the chamber. For example, along the outer surface of the wall forming the distal edgecan be an annular shelfa extending radially toward the lip portionto further occupy the space therebetween, as seen in. The exterior annular shelfa would preferably present a barrier to an string, wire or other long flexible instrument which may be manipulated in between the first plate memberand the distal edge.

The second plate memberis preferably coupled to the first plate member to further define one or more cover plate assembly openingswhich engage the ends of the lever membersa,b. More specifically, shown in the exploded views ofis the cover plate assembly. The first plate memberincludes an openinga, and the second plate memberincludes a plate openingb. In one preferred assembly, the openinga of the first plate memberis an elongated closed formed opening, and the openingb of the second plate member is an open ended slot. Upon the assembly and overlap of the first and second plate members,, the respective opening and slota,b cooperate to form the preferred closed form elongated single openingas seen in. The first and second plate members,can include additional or alternatively dimensioned open or closed formed openings, cut-outs, slots, slits, voids, perforations or depressions.

Referring again to, the openingis preferably dimensioned such that ends of the leversa,b engage the axial ends of the openingso as to locate the lever membersa,b within the chamberto support the deflector and closure assemblies as described above. Although, the openings of the cover plate assemblyare shown as substantially rectangular, other geometries are possible such as, for example, oval or another polygonal shape provide the opening can be engaged with the ends of the lever member in a substantially close fit arrangement. Preferably, the plate engaging ends of the lever membersa,b are configured so as to engage the plate assembly openingin a substantially normal direction to the surface of the plate assembly. Thus, the end portion of the lever members preferably define an obtuse included angle α ranging from about 105° to about 115°, is preferably about 112° and is more preferably about 108°, with the remainder of the lever membersa,b, as seen in. Moreover, the openingis preferably located centrally to the cover plate assembly, thereby angling the lever membersa,b relative to one another to form the supporting frame for the bridge elementand the deflector and closure assemblies as described above. More preferably, the openingis located about the center of the cover plate assemblyand intersecting the longitudinal axis A-A such that the ends of the lever membersa,b are located within the axial flow path defined by the outletof the passageway.

The ends of the lever membersa,b preferably occupy only a portion of the entire area of the opening, for example, 30 to 50 percent of the entire available space defined by the opening. Thus to fully occupy the opening, provide the close fit between components and maintain the concealed nature of the complete sprinkler assembly, the lever assemblyfurther includes a retaining member or plugto horizontally space the ends of the lever membera,b into close engagement with the ends of the opening. The central plugcan be embodied as a small resilient member for installation into the plate assembly openingafter locating the plate assemblyabout the distal portion of the body. Alternatively, the plugcan be embodied as an enlarged wedge shaped spacer or retaining bar located between the lever membersa,b prior to locating the plate assemblyabout the distal portion of the body.

The second plate memberis preferably thermally coupled to the first plate member. The first and second plate members,are preferably coupled together by a fusible thermally sensitive material such as, for example, a eutectic solder material rated to melt in the presence of sufficient heat generated by, for example, a fire event. Accordingly, the trigger assemblypreferably incorporates or includes the cover plate assemblyas a thermally rated link device to thereby define the thermal rating of the sprinkler. Preferably, the cover plate assemblyis configured to define a thermal rating for the sprinklerranging between 140° F. and 212° F.; more preferably, the sprinkleris thermally rated for 165° F. In addition, the cover plate assemblycan be configured as a standard response or a fast response link device. Preferably, the solder material and the link device define an response time index (RTI) of less than 50 (m-s).

Referring again to, disposed between the first plate memberand the second plate memberis the solder material. The area to be soldered is preferably equivalent to the area defined by the surface area of the second plate memberto be joined to the first plate member. Accordingly, for a preferred second plate member, as shown for example in, the areas to be soldered is about 0.4 square inches (in.) to about 0.5 inand is preferably about 0.45 in.. In order to ensure that the solder coupling between the plate members is of an appropriate thickness, at least one of the plate members, preferably the smaller second plate member, includes one or more dimple membersthat project into the space between the plate members,at a preferred dimple height of about 0.0010 inches to about 0.0015 inches. The dimple membersact as a spacer between the plates as the solder material fills the interstitial space to control the thickness of the solder preferably to height equivalent to the dimple height. Accordingly, the preferred plate assemblydefines a weld area to height ratio ranging from about 300:1 to about 450:1. The thickness of the solder can define the thermal responsiveness of the solder and therefore define the thermal responsiveness of the cover plate assembly or linkand the sprinkler. Moreover, the height of the solder in the axial direction, i.e., the thickness can further define the bonding strength of the solder. Should the solder height be too low, there may be too much of an alloy present due to the heat generated in applying the solder such that the solder does not retain its expected thermal responsiveness. Conversely, if the solder height is too high then the solder connection may not be sufficiently strong enough in shear, i.e., the direction orthogonal to the longitudinal axis, to resist the force of the lever membersa,b and maintain the first and second plate members coupled to one another.

To further ensure that the surfaces of the plate members,are correctly oriented relative to one another so as to properly define the one or more cover plate assembly openings, each of the first and second plate members,preferably includes a depression or openinga,b and a corresponding projectiona,b for respectively containing therebetween the thermally sensitive material. The cooperation between the depressionsand the projectionsensures that the second plate memberis properly oriented and engaged with the first plate memberto define the plate openingfor engagement with the ends of the lever assembly. More preferably, the depressionsand the projectionsare offset relative to the center point of each plate member,to further ensure that the appropriate mating faces are engaged. Alternatively, other mating features can be incorporated respectively into the first and second plate members,to ensure proper orientation and engagement of the plate members.

The first and second plate members,of the assemblyare preferably copper, and in their preferred assembly, the plates,are cleaned and de-oxidized. With an appropriate flux applied to their mating surfaces, the plates are pressed together and a preformed pelletof sufficient volume is disposed within each cavity formed by the engaged depressionsand projections. The assembly is heated to distribute the solder material between the first and second plate members,, filling the space therebetween. The assembly is preferably heated to produce a solder fillet around the perimeter of the second plate member. A preferred preformed solder pelletis shown for example in. The solder pelletis preferably a material of Indalloy 158 from INDIUM CORP. or equivalent solder having a preferred composition of 50% Bi, 26.7% Pb, 13.3 Sn, and 10% Cd.

Upon exposure to a sufficient level of heat, the thermally sensitive material between the plates melts thereby allowing the first and second plate members,to separate, and allow the lever assembly to pivot and actuate the sprinkler. The first plate memberpreferably defines a larger surface area than the second plate member. Where each of the first and second plate members,or their assembly is substantially circular, the second plate memberis preferably located eccentrically relative to the first plate membersuch that the center points of the first and second plate members,are coaxially aligned along an axis skewed relative to the longitudinal axis A-A. Alternatively, each of the first and second plate members,can define a center point, which can further be coaxially aligned in the cover plate assemblyand substantially parallel to the longitudinal axis A-A. Further alternatively, the cover plate assembly, can define a geometry other than substantially circular, such as, for example, oval, rectangular or polygonal.

The thermal performance of the cover plate assemblyas a thermal link device can be further defined by the material and thickness of the material forming the individual plate members,of the assembly. Preferably, the thickness of the first and second plate members,is such that the cover plate assemblypresents a sufficiently rigid and durable structure. However, the plate members,should not be so thick so as to adversely effect the desired and preferably predictable thermal performance of the cover plate assembly. Preferably, each of the first and second plate members,are constructed from a copper material ranging in thickness from about 0.007 inches and 0.01 inches, preferably ranging from about 0.0070 inches to about 0.0080 inches and is preferably about 0.0075 inches thick. Alternatively, the first and second plate member,can be made of other thermally responsive materials such as nickel preferably having a thickness of about 0.007 inches. Moreover, the first and second plate members can be constructed of any material of any thickness provided the assembly of the first and second plate members provides adequate thermal responsiveness.

Preferably, all the exposed surfaces of the cover plate assemblyare coated to protect the assembly against corrosion from the elements of the surround environment in which the sprinklermay be placed. Corrosion could adversely effect the thermal performance of the cover plate assemblyand inhibit its capability to serve as an effective link device in the trigger assembly. Preferably, the edge surfaces defining the thickness of the assemblyare at a minimum double coated to ensure proper protection. These edge surfaces, for example at the periphery of the first plate memberor at the edges defining the opening, are thin and therefore do not present a large surface area to which a coating may adhere. In particular, the cover plate assemblyis covered with a two part coating including a self-etching primer and a polyurethane coating. Such a two-part coating is well known in the art. Alternatively, the cover plate assemblycan be coated with a polyester coating which is preferably configured as a powder applied paint. Further in the alternative, a protective coating may be applied in which the coating is embodied in an epoxy coating. Other coatings know in the art may also be utilized.

More preferably, the cover plate assemblyis covered with a paint coating to satisfy one or more standards and test protocols, such as for example, the operation and corrosion test standards under UL Standard 199 (2005), which is incorporated by reference in its entirety. The preferred coating includes a prime coat, preferably a fast drying pretreatment type, 2 package, acid catalyzed vinyl washcoat such as, for example, INDUSTRIAL WASH PRIMER CC-A2 from SHERWIN WILLIAMS as described in Sherwin William Chemical Coating data sheet CC-A2 (11/06) available at Internet URL:<http://www.paintdocs.com/webmsds/webPDF.jsp?SITEID=STORECAT&prodno=035777435052&doctype=PDS&lang=E&#x3e;. The preferred coating further includes a top coat of a corrosion inhibiting epoxy polyamide coating such as, for example, MILGUARD-53022 CORROSION INHIBITING L & C FREE EXPDXY PRIMER from SIMCO COATINGS INC., as described in Simco Mil Spec Paint data sheet Mil-P-53022 available at Internet URL:<http://www.simcocoatings.com/mil-p-53022b.html&#x3e;. The coating is preferably applied to a thickness of ranging from about 0.0005 inches to about 0.002 inches.

Accordingly, the preferred coating combination provides a means to provide corrosion protection to the plate assemblywithout interference to the link responsiveness, operation or separability of the plate members,. With regard to the ability of the plate members,to separate upon proper thermal response, i.e., melting of the solder in the presence of a sufficient heat source, the coating preferably allows the plate members,to separate when subject to a separation force of less than 6 lbs-force and preferably separate at 3 lbs-force. To test the separability of a coated plate assembly, the assembly is placed in the test stand schematically shown into simulate operation of the link, as described below when installed in the sprinkler. More specifically, a plate assemblyheated to within 20 degrees Fahrenheit of its operational temperature is placed in a heated bath with the first plate memberanchored, preferably at an edge forming the openingby a hooka. The second plate memberis engaged by a hook or anchorb preferably at an edge forming the opening. The hookb is connected to a pulley system under an adjustable load W. The bath is incrementally heated, preferably at a rate of one degree Fahrenheit per minute (1° F./min) to its nominal operational temperature of 165° F. With the bath and linkat the operational temperature, the load is increased at one-half pound increments up to six pounds. The link assemblysuccessfully satisfies the test upon complete separation of the plate members,when subjected to a load of less than six pounds and preferably at three pounds.

With regard to corrosion testing, a preferred coated assemblyand sprinklerfurther satisfied the 10-Day Corrosion Test as provided by UL Standard 199 (2005) which is incorporated by reference in its entirety. Under the specified 10-Day test, the external parts of the sprinklerwithstood an exposure to salt spray, hydrogen sulfide and carbon dioxide-sulfur dioxide atmospheres when subjected to (i) a twenty percent salt spray test; (ii) a moist hydrogen sulfide air mixture test; and (iii) a moist carbon dioxide-sulfur dioxide air mixture. During the exposure tests, the passageway of the sprinklerwas filled with de-ionized water and the inlet of the sprinkleris sealed by a plastic cap in accordance with the test procedures. After the sprinklerwas subjected to the exposure test, is then satisfied test for operation, responsiveness and sensitivity under the UL Standard 199 procedures for the oven heat test, sensitivity oven tests and the room heat test as specifically detailed and required in Section 41 of UL 199 (2005) and the sections referenced therein.

The assembled sprinkleris preferably pressure rated to maintain a static fluid pressure of about 500 pounds per square inch (psi). Referring, for example, to, in one preferred method of assembling the sprinkler, the bodyis positioned in an upright position to allow gravity to position the closure and deflector assemblies,into their initial sealed and first positions. More preferably, a threaded tool is inserted into the passageway, and threaded into engagement with the partial boreof the button. A force is applied to the tool toward the proximal portionof the bodywhich further brings the frustroconical tip of the closure buttoninto the passagewayand further compresses the biasing elementin between the flangeof the buttonand the distal portionof the bodyforming the outletsuch that the biasing elementis substantially flat. The flangeis preferably dimensioned to be greater than the diameter of the outletin order to prevent collapse of the spring discinto the passageway. With the closure elementpartially engaged in the passagewayb and the deflector platein the retracted first position, the bridge elementcan be lowered and its preferred central hole can be placed into engagement with the upward projection of the closure element, thereby exposing the channelof the bridge element. The ends of the lever membersa,b can then be positioned in the channeland further preferably wedged into a pivotable engagement with the annular shelfformed along the inner surfaceof the annular wallwith the walls of the bridge elementdefining the channelsupporting the ends of the lever membersa,b.

The opposite end of the lever membersa,b are then preferably brought into position for engagement with the cover plate assembly. The first and second plates are preferably arranged and thermally coupled together, as previously described, to form the preferably substantially circular cover plate assemblywith the central opening. The lever membersa,b are spaced apart by the retaining member. The retaining memberis preferably generally triangular in shape with two substantially converging surfaces configured to cradle the lever membersa,b. Each of the converging surfaces preferably include tabsa,b to further cradle and support the lever membersa,b against the retaining member. Extending between the converging surfaces is a planar surface for engagement with the channelof the bridge element. With the planar surface of the retaining memberdisposed between the lever members in the channel, the lever membersa,b are brought into engagement with the converging surfaces of the retaining member. The cover assemblyis disposed over the distal end of the bodysuch that the openingis then brought into close tolerance engagement about the lever membersa,b and the retaining member. Preferably, the gap clearance between the lever members, the plug and the edges forming the openingis about 0.005 inches. The threaded tool is preferably disengaged from the partial boreof the buttonand the spring disc is released to bias the closure elementand the bridge elementin the distal direction of the sprinkler. The bias force of the spring disccompresses the lever assemblyinto further close engagement with the and the shelfand the openingof the cover plate assemblyto provide a close fit and secure arrangement of parts for the trigger assemblyand the sprinkler.

In an alternative method, the ends of the lever membersa,b are held close together without the use of a retaining member. Instead, the cover plate assemblyis disposed over the distal end of the body, and the openingis brought into engagement with the lever membersa,b. With the ends of the lever membersa,b disposed in the central opening, a central plug′ is inserted between the lever ends to bring the openingand the ends of the lever membersa,b into the close fit engagement. The plug′ shown in the alternative embodiment of the sprinkler, shown inis preferably a resilient two prong member for wedged engagement into the openingadjacent the ends of the levera,b. The prongs of the plug′ are preferably configured with one or more surfaces to engage the internal surfaces of the first plate memberand prevent removal of the plug′ from the opening.

As described above, the sprinkleris preferably disposed within a mounting element or escutcheonfor flush mount installation against a ceiling surface. To install the sprinkler, the sprinkleris preferably threaded into an appropriately sized tee-type or other pipe fitting that is preferably mounted along a branch supply line of a sprinkler system. To facilitate installation of the sprinkler, the outer surface of the 34 of the annular wallpreferably includes one or more tool engaging surfaces, as seen for example in, radially disposed about the outer surface. Preferably, the tool engaging surfacesform the maximum gap width between the outer surfaceof the annular walland the inner surface of the escutcheon. The maximum gap width preferably is about 0.065 inches. A toolhaving a plurality of planar projectionsis preferably provided for engagement with the tool engagements surfaces. The projectionsof the toolcan engage the surfacesto thread the sprinklerinto an installed position or alternatively to unthread the sprinkler for removal. The toolcan further include a socketfor receiving a tool extension member, such as a socket handle for operating the toolat a distance. For example, the toolcan be used with an extension member to install the sprinkler through an opening in a ceiling in which the opening is too small for an operator's hands to maneuver through.

In a preferred body of the sprinkler, shown for example in, the tool engagement surfacesa,b,c are preferably radially spaced so as to be able to orient the armsa,b upon installation. Specifically, each the central axes of two engagement surfacesa,b passing through the center point of the sprinkler discharge end face are located forty degrees (40°) relative to the axis along which the through holesa,b are spaced such that the central axes are angularly spaced by 100°. The central axis of the third engagement face passes through the center point of the sprinkler end face perpendicular to the axis along which the through holesa,b are spaced so as to locate the third engagement facec at an angle of about 130° relative to each of the first and second engagement surfacesa,b. Because of the orientation of the engagement surfacesa,b,c are oriented relative to the through holesa,b, the tool can be used, upon installation of the sprinklerorient or align the deflector assembly armsa,b relative to, for example, the branch or feed line of the sprinkler. Moreover, due to the angular relation of the engagement surfaces and the prongs on the tool, the toolcan only engage the end face of the sprinklerin a single manner.

The completely assembled and installed sprinkleris preferably configured to maintain a static pressure of fluid of about 500 pounds per square inch (psi). More specifically, the arrangement of the lever assemblyis configured to maintain the deflector assemblyin the first position and the closure elementin the sealed position within the outletunder a static fluid pressure load of up to 500 pounds per square inch (psi). Therefore, provided the lever membersa,b are restrained from pivoting about their engagement points with the inner surfaceof the annular wall, the arrangement of the lever membersa,b provides a frame structure sufficient to independently maintain the initial and sealed positions of the deflector assemblyand the closure assembly. Shown in, is a cross-sectional view of the lever and cover plate assemblies,overlaid by a static force diagram showing the manner in which the forces about the lever assemblysupport the closure assemblyin the sealed position. More specifically shown is a fluid force Fand spring force Frespectively applied in a distal direction by a fluid (gas or liquid) and a preferred Belleville spring disc. The fluid force Fand a spring force Fcan be distributed about the bridge elementand the further characterized by distributed resolved forces Fapplied at each end of the bridge elementacting in a distal direction, as shown for example, upon the lever memberb. Preferably the resolved force Fis preferably determined by:F=[(F+F)/2]*sin β

where Fis equal to the pressure of fluid multiplied by the area at the inlet, i.e. F=Pressure*[(Π/4)*Dia.], and β is the angle formed between the longitudinal axis A-A and the lever memberb.

In addition to the resultant force F, a normal force Facts on the lever memberb, for example, by the friction engagement of the lever memberb with the shelfat the point P. These forces tend to bias and pivot the lever member about the point of engagement P, which results into a bias force transferred by the lever membersa,b against the plate members,of the cover plate assemblyat the edges forming the plate assembly opening. In order for the lever memberb to support the bridge elementand hold the closure elementin its sealing position, the lever memberb must be a static member. Accordingly, in response to the outward biasing force, the plate assemblyexerts an equal and opposite reaction force Fapplied to the end of the lever memberb. More specifically, the lever memberb is static in its sealing configuration, and thus, the moments M about the point P at which the lever memberb engages the shelfmust sum to zero. Looking at the location of the forces acting on the lever memberb while in its static position engaged with the shelfand the plate assembly, a moment equation can be derived and the plate assembly reaction force Fcan be solved for as follows. From static mechanics, M=Fd where M is moment about a point P, F is an applied force, and d is the orthogonal distance between the direction of the force F to the point P. For the lever memberb in, the moment equation can be written as:ΣM=Fd1+Fd2+Fd3 where

d, d, dare respectively the orthogonal distances from the direction of the respective forces F, F, and Fto to the engagement point P preferably at the shelf, where further

d=0

d=x

d=y