Residential flat plate concealed sprinkler

A pendant sprinkler preferably includes a body having an inner surface defining a passageway. The passageway includes an inlet and an outlet spaced apart along the longitudinal axis and defines a K-factor of about 5. The sprinkler also includes a closure assembly adjacent the outlet to occlude the outlet and a thermally responsive support means for maintaining the closure assembly adjacent the outlet. Also provided are means for distributing a flow of fluid over a protection area ranging from about 144 square feet to about 400 square feet, the fluid distribution having a density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2) so as to define a range of minimum operating pressures ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.) and a range of minimum operating fluid flows ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20 gpm.). The sprinkler preferably includes a thermally responsive plate means for maintaining a minimum spacing between the outlet and the means for distributing.

TECHNICAL FIELD

This invention relates generally to residential sprinklers, systems and methods of use. More specifically, the invention is directed to residential concealed flat plate sprinklers and their methods of use in residential sprinkler systems.

BACKGROUND OF THE INVENTION

Residential automatic fire protection sprinklers are typically designed to specific performance criteria or standard that has been accepted by industry. The performance criteria establishes the minimum performance standards for a given sprinkler to be consider sufficient for use as a residential fire protection product. For example, Underwriters Laboratories Inc. (UL) “Standard for Safety for Residential Sprinklers for Fire Protection Service” (October 2003) (hereinafter “UL 1626”), which is incorporated herein in its entirety be reference thereto, is believed to be an accepted industry standard.

The National Fire Protection Association (NFPA) also promulgates standards relating to residential fire protection such as, for example, (i) NFPA Standard 13 (2002) (hereinafter “NFPA 13”); (ii) NFPA Standard 13D (2002) (hereinafter “NFPA 13D); and (iii) NFPA Standard 13R (2002) (hereinafter “NFPA 13R”) (collectively “NFPA Standards”) each of which is incorporated in its entirety herein by reference thereto. In order for a residential sprinkler to be approved for installation under NFPA Standards, such sprinkler typically must pass various tests, for example, tests promulgated by UL under UL 1626, in order to be listed for use as a residential sprinkler. Specifically, UL 1626 generally requires a sprinkler, as described in Table 6.1 of Section 6, to deliver a minimum flow rate (gallons per minute or “gpm”) for a specified coverage area (square feet or “ft2”) so as to provide for a desired average density of at least 0.05 gpm/ft2. For instance, for a 16 ft.×16 ft. room size with a 256 ft2coverage area, a residential sprinkler that can provide the minimum density in an optimum manner would utilize a flow of water of thirteen gallons per minute (13 gpm). Thus, 13 gpm is the minimum flow listing for a coverage area of 256 ft2. In addition to a sprinkler configuration providing the minimum density at the minimum flow listing, the sprinkler advantageously would achieve the minimum flow listing at the lowest possible pressure. The minimum flow rate tabulated in Table 6.1 can be used to calculate a predicted minimum fluid pressure needed to operate a sprinkler by virtue of a rated K-factor of the sprinkler. A rated K-factor of a sprinkler provides a coefficient of discharge of the flow passage of the sprinkler, is defined as follow:

where Q is the flow rate in GPM and p is the pressure in pounds per square inch gauge. Thus, for a rated K-factor of 4.9 and a minimum flow rate of 13 gpm, the residual or calculated minimum pressure is seven pounds per square inch (7 psi.).

In order for a sprinkler to pass actual fluid distribution tests as described in Sections 26 and 27 of UL 1626 however, the actual minimum pressure of the test sprinkler may differ from the calculated or predicted minimum pressure, which can be calculated using the given minimum flow rate of Table 6.1 in UL 1626 and the rated K-factor of the sprinkler. Further, the actual minimum fluid flow rate to pass these distribution tests of UL 1626 for a specified coverage area may even be higher than the tabulated minimum flow rate given in Table 6.1 of UL 1626. Consequently, any attempt to provide for a listed sprinkler (i.e., an operational sprinkler suitable for the protection of a dwelling unit) cannot be predicted by applications of a known formula to known residential sprinklers.

In order to provide an aesthetically appealing configuration of a sprinkler for use in a residence, the sprinkler may be configured to use a flat plate to conceal the sprinkler itself until the sprinkler is actuated. This type of sprinkler is known as a residential flat plate concealed sprinklers. It is believed that known residential flat plate concealed sprinklers that are configured for use in a pendent manner range in K-factor from 4.1 to 5.6 (gpm/psi1/2).

In order for a residential flat plate concealed sprinkler to operate, a two step operation occurs when a fire hazard is to be addressed. First, the cover of the concealed sprinkler must disengage from the sprinkler. Second, the sprinkler must operate to allow water to flow. Because of the two step operation of the residential flat plate concealed sprinkler, and that such residential sprinklers are typically fully recessed into a ceiling, residential flat plate concealed sprinklers have an increased flow rate above the minimum flow listings in order to successfully pass UL 1626 fire tests.

It is believe that known residential flat plate concealed sprinklers have been unable to successfully pass the UL 1626 test standard for a 16 ft.×16 ft. room size fire test at both the minimum flow rate (13 gpm) and the minimum operating pressure (7 psi). Furthermore, it is also believed that known residential flat plate concealed sprinklers have been unable to successfully achieve the minimum flow rates of seventeen gallons per minute (17 gpm.) for an 18 ft.×18 ft. room size and twenty gallons per minute for a 20 ft.×20 ft. room size in accordance with UL 1626.

DISCLOSURE OF INVENTION

A preferred embodiment of the present invention is believed to be the first residential automatic sprinkler with a flat plate that conceals the sprinkler to successfully complete UL 1626 distribution and fire testing with both minimum flow (13 gpm) and minimum pressure (7 psi) for an area as large as 16 ft.×16 ft. In addition, the sprinkler of the preferred embodiment is believe to be the first known sprinkler that has successfully completed distribution and fire tests in the 18 ft.×18 ft. and 20 ft.×20 ft. room sizes, with minimum flows of 17 gpm and 20 gpm respectively. More specifically, the sprinkler can provide a minimal flow of seventeen gallons per minute (17 gpm) in successful fluid distribution and fire tests for a 324 square feet area (18 ft.×18 ft.) at about twelve pounds per square inch (12 psi.), and further provide a minimal flow of twenty gallons per minute (20 gpm.) for a 400 square foot test area (20 ft.×20 ft.) at less than seventeen pounds per square inch and even more preferably at about 16.7 psi. The preferred embodiment utilizes a sprinkler with a nominal discharge coefficient (K Factor) of 4.9 gpm/psi1/2. Through the specific combination of a deflector and a projection cone geometry, the preferred embodiment of the sprinkler has achieved the specified residential listings for both flow and pressure.

One preferred embodiment provides a residential flat plate concealed sprinkler for the fire protection of an area ranging from about 144 square feet to about 400 square feet. The sprinkler preferably includes an outer housing having an inner surface defining a chamber and a body at least partially disposed within the chamber. The body preferably has an inlet and an outlet spaced along a longitudinal axis, the outlet having a minimum design fluid flow ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20 gpm) and the inlet having a minimum design input fluid pressure ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.). The body further preferably includes an inner surface defining a passageway for communication between the inlet and the outlet. The at least one guide member has a proximal end and a distal end. The proximal end is preferably coupled to the body and the distal end having telescopic relative movement relative to the outlet in direction parallel to the longitudinal axis. The sprinkler further preferably includes a deflector plate assembly for distributing a flow of fluid over the protected area. The deflector assembly is preferably coupled to the distal end of the at least one guide member so that the deflector has a first position distal of the outlet and a second position distal of the first position. The deflector assembly includes a plate member and a projection member coupled to the plate member to define a proximal surface substantially orthogonal to the longitudinal axis and spaced axially from the outlet and a distal surface distal of the proximal surface and orthogonal to the longitudinal axis. The distal surface preferably defines an oblong perimeter circumscribed about the longitudinal axis and further including a plurality of slots substantially equiradially spaced about the longitudinal axis. Each slot has a substantially straight portion initiating from the perimeter and extending radially toward the longitudinal axis to define a slot length and further having a slot width. The plurality of slots also further defines a first slot group having a first slot length and at least a second slot group having a second slot length smaller than the first slot length.

In another preferred embodiment, provided is a pendant concealed sprinkler that includes an outer housing and an inner housing coaxially aligned along a longitudinal axis. The sprinkler further includes a body having at least a portion disposed in the inner and outer housing. The body preferably has an inner surface defining a passageway including an inlet and an outlet spaced apart along the longitudinal axis and defining a K-factor of about 5. The sprinkler further preferably includes a closure assembly to occlude the outlet and a thermally responsive trigger element having a first state aligned with the longitudinal axis to support the closure assembly adjacent the outlet and a second state to displace the closure assembly from the outlet. The sprinkler further preferably provides a deflector assembly distal of the outlet. The deflector assembly preferably has a plurality of deflecting surfaces substantially perpendicular to the longitudinal axis and a plurality of slots in at least one of the deflecting surfaces to provide a distribution of a fluid over a protection area a protection area ranging from about 144 square feet to about 400 square feet, the fluid distribution having a density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2) for a minimum operating pressure and a minimum operating fluid flow corresponding to the protection areas. The minimum operating pressures range from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.) and the range of minimum operating fluid flows ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20 gpm). The preferred sprinkler further includes a plate assembly having a cover plate and a thermally responsive fastener coupling the plate assembly to the outer housing such that the cover plate engages the deflector assembly and contains the deflector assembly within the outer housing.

In yet another preferred embodiment, a sprinkler preferably includes a body having an inner surface defining a passageway for carrying a fluid. The passageway includes an inlet and an outlet spaced apart along the longitudinal axis and defines a K-factor of about 5. The sprinkler also includes a closure assembly adjacent the outlet to occlude the outlet and a thermally responsive support means for maintaining the closure assembly adjacent the outlet. The preferred sprinkler also provides means for distributing a flow of fluid over a protection area ranging from about 144 square feet to about 400 square feet, the fluid distribution having a density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2) so as to define a range of minimum operating pressures ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.) and a range of minimum operating fluid flows ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20 gpm). In addition, the sprinkler preferably includes a thermally responsive plate means for maintaining a minimum spacing between the outlet and the means for distributing.

Another embodiment according to the present invention provides a method of fire protecting an area with a sprinkler having a coverage area no greater than 256 square feet. The coverage area is preferably about 256 square feet and further be about 196 square feet or further in the alternative be about 144 square feet. The method includes discharging a fire fighting fluid at a flow rate of about thirteen gallons per minute (13 gpm) from a sprinkler body having a K-factor of about 5 and more preferably about 4.9. The method also includes distributing the fluid over the area at a fluid design density of about 0.05 gallons per minute per square foot (0.05 gpm/ft2). The method also preferably The method includes introducing the fluid to the body at an operating pressure of about seven pounds per square inch (7 psi.).

Another preferred embodiment provides a method of fire protecting an area with a sprinkler having a coverage area measuring greater than 256 square feet but no greater than 324 square feet. The method preferably includes discharging a fire fighting fluid at a flow rate of about seventeen gallons per minute (17 gpm) from a sprinkler body having a K-factor of about 5 and further distributing the fluid over the area at a fluid design density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2). Preferably the fluid is introduced to the sprinkler at an operating pressure of about twelve pounds per square inch (12 psi.).

In yet another alternative embodiment of the method, a method is provided for protecting an area having a sprinkler coverage area measuring greater than 324 square feet but no greater than 400 square feet. The method includes discharging a fire fighting fluid at a flow rate of about twenty gallons per minute (20 gpm) from a sprinkler body having a K-factor of about 5 and distributing the fluid over the area at a fluid design density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2). Preferably, the fluid is introduced to the body at an operating pressure of about seventeen pounds per square inch (17 psi.) and more preferably about 16.7 psi.

In yet another embodiment of any of the above described methods, distributing the discharged fluid includes distributing the fluid as per Section 26 of UL 1626 and applying the fluid over the coverage area such that the rate of application is at least 0.02 gallons per minute per square foot (0.02 gpm/ft2), wherein no more than four areas measuring one square foot have an application rate of at least 0.015 gallons per minute per square foot (0.05 gpm/ft2). Any of the above methods can further define a minimum sprinkler to sprinkler spacing of about eight feet (8 ft.).

Another preferred aspect of the present invention provides a residential sprinkler system that preferably includes a fluid supply source, a maximum coverage area in a residential dwelling, the coverage area being no greater than 256 square feet; and a residential sprinkler having a body with an inlet and an outlet and a K-factor rating of about 5 and more preferably about 4.9. The sprinkler is preferably coupled to the fluid supply source such that the supply provides a minimum operating pressure to the inlet at about seven pounds per square inch (7 psi.) and the outlet provides a discharge flow having a flow rate of about thirteen gallons per minute. The sprinkler preferably includes a deflector assembly to deflect the discharge flow and define a distribution pattern providing a fluid density over the coverage area of about 0.05 gallons per minute per square foot (0.05 gpm/ft2).

In yet another embodiment of the system preferably includes a maximum coverage area in a residential dwelling being greater than 256 square feet and less than about 324 square feet. The preferred system further includes a residential sprinkler having a body with an inlet and an outlet and a K-factor rating of about 5. The sprinkler being coupled to the fluid supply source such that the supply provides a minimum operating pressure to the inlet of about twelve pounds per square inch (12 psi), and the outlet provides a discharge flow having a flow rate of about seventeen gallons per minute (17 gpm).

In another alternative embodiment of the system, the maximum coverage area is preferably greater than about 324 square feet and less than about 400 square feet. The system further preferably includes at least one residential sprinkler having a body with an inlet and an outlet and a K-factor rating of about 5. The sprinkler is preferably coupled to the fluid supply source such that the supply provides a minimum operating pressure to the inlet of about seventeen pounds per square inch (17 psi), and the outlet provides a discharge flow having a flow rate of about twenty gallons per minute (20 gpm). The sprinkler includes a deflector assembly to deflect the discharge flow and define a distribution pattern the pattern providing a fluid density over the coverage area of at least 0.05 gallons per minute per square foot (0.05 gpm/ft2).

MODE(S) FOR CARRYING OUT THE INVENTION

Shown inFIGS. 1-2is an illustrative embodiment of a concealed pendant residential fire sprinkler10that can be used in residential applications, for example, to protect a floor area of a compartment in the residential dwelling unit. As used herein, the term “residential” is a “dwelling unit” as defined in the 2002 Edition of NFPA 13D and NFPA 13R, which can include commercial dwelling units (e.g., rental apartments, lodging and rooming houses, board and care facilities, hospitals, motels or hotels) to indicate one or more rooms, arranged for the use of individuals living together, as in a single housekeeping unit, that normally have cooking, living, sanitary, and sleeping facilities. The residential dwelling unit normally includes a plurality of compartments as defined in the NFPA Standards, where generally each compartment is a space that is enclosed by walls and ceiling. Accordingly, the sprinkler10can be configured for use in a residential sprinkler system, preferably a wet pipe residential sprinkler system for: (i) one and two family dwellings and mobile homes per NFPA 13D; (ii) residential occupancies up to and including four stories in height per NFPA 13R; or (iii) any other occupancy as per NFPA 13.

Referring toFIG. 1, a partially cut-away view of a preferred embodiment of the residential sprinkler10is shown coupled to a sprinkler system, preferably a wet sprinkler system100, in a plenum space above a ceiling200of a known construction such as, for example, gypsum wallboard or ceiling tile. The sprinkler10preferably includes a body12configured to couple the sprinkler10to the sprinkler system100. Preferably, the sprinkler10is coupled to a branch line of the sprinkler system100by way of a threaded connection between the body12and a corresponding fitting on a branch line of the sprinkler system100. Alternative connections are possible provided the connection facilitates fluid communication between the sprinkler system100and the sprinkler10in a manner described herein below.

The sprinkler10preferably includes a support cup or outer housing14disposed about the body12. The outer housing14provides a chamber for housing the sprinkler operational components such as, for example, the trigger and deflector assemblies. Connected below the housing14is a detachable cover plate assembly16providing means to conceal the sprinkler components from view beneath the ceiling200. The cover plate assembly16preferably includes a substantially flat plate18that presents a low profile with respect to the ceiling200. The plate18can include decorative or textured surface treatment or coloring so as to aesthetically blend in or coordinate with the surrounding environment. In operation, a portion of the plate assembly16is configured to separate from the outer housing12and/or the operational components of the sprinkler10thereby allowing the sprinkler10to actuate and discharge a fire fighting fluid over the area beneath the ceiling200.

A cross-sectional view of the sprinkler10is provided inFIG. 2. The body12is shown with the preferred outer thread11for coupling to the sprinkler system100and further preferably including a multi-flat area13for engagement with an installation tool such as, for example, a socket-type wrench (not shown). The multi-flat area13can include, for example, six contiguous flat sides to form a hexagon shaped outer perimeter to the body12about which the installation tool can grip to thread the sprinkler10into or out of the sprinkler system100.

The sprinkler10is preferably embodied as a concealed sprinkler. Accordingly, preferably threadedly engaged with the outer threads11of the body12is the outer housing14. The outer housing14preferably includes an interior peripheral edge defining a centralized bore41. The body12can be disposed through the central bore41and the interior peripheral edge of the outer housing14can engage the outer threads11of the body12to couple the body and the housing to one another. The multi-flat portion13of the body12can be dimensioned so as to form a stop that engages an inner surface of the outer housing14to limit the axial engagement of the body12through the central bore42of the outer housing14.

The inner surface of the outer housing14is preferably radially spaced from the longitudinal axis A-A to define a chamber44for preferably surrounding and housing the operational components of the sprinkler10. The inner surface of the housing14can include a coupling mechanism46for coupling to the cover plate assembly16. Preferably, the housing14includes a rolled thread46aalong the inner surface for engagement with a portion of the plate assembly16to couple the elements together.

Shown inFIG. 3is a cross-sectional view of the preferably detachable plate assembly16. The cover plate assembly16preferably includes a retaining sleeve portion48having a plurality of projections46B for threaded engagement with the interior thread46A of the outer housing14to couple the plate assembly16and outer housing14A together. Alternatively, retaining sleeve portion48can include a threaded portion for mutual engagement with the interior thread46aof the outer housing14. The sleeve preferably includes a mounting surface50for engaging the surface of the ceiling200thereby limiting the axial engagement of the plate assembly16with the outer housing14.

A cover plate member is attached to the retaining sleeve48such that it substantially conceals the chamber of the outer housing14thereby concealing the operational components of the sprinkler10such as, for example, the deflector assembly42as seen inFIG. 2. The cover plate member is preferably attached to the retaining sleeve by a thermally responsive coupling52such as, for example, a tab or beading of solder52, which is rated to hold the plate member to the retaining sleeve48up to a desired temperature. Above the threshold temperature, the solder52melts releasing the cover plate member and exposing the operational elements of the sprinkler10to address the heat source. The solder52is preferably rated between 115° F. to about 140° F. and more preferably from about 117° F. to about 137° F. and is even more preferably about 135° F. More preferably, three tabs of solder52are applied radially about the longitudinal axis. To facilitate the separation of the cover plate member and the retaining sleeve48, the plate assembly16further preferably includes an ejection spring53which biases the cover plate member away from the retaining sleeve48. The ejection spring53can be, for example, a compression spring member disposed between the deflector assembly42and the plate member18. As described above, the cover plate member is preferably a substantially flat plate18to provide a low profile relative to the ceiling200. Alternatively, the cover plate member18can include a step or curved profile so as to present, for example, a concave surface relative to the view below the ceiling200.

The operational components of the sprinkler10can individually and collectively define sprinkler performance, i.e. water distribution and compliance with known sprinkler standards such as, for example, the October 2003 edition of UL 1626. More preferably, the operational components of the sprinkler10provide for a heat sensitivity or thermal responsiveness along with water distribution characteristics that can effectively address a residential fire and thereby improve the chance for occupant to escape or be evacuated. The body12is an operational component having, as seen inFIG. 2, an inner surface20defining a passageway or conduit22. The passageway22provides communication between a body inlet24and a body outlet26spaced apart along the sprinkler longitudinal axis A-A. The inlet24is configured to receive fluid from the sprinkler system100and the outlet26is configured to discharge the fluid for distribution over a protection area beneath the sprinkler10. The body12is preferably configured to define a discharge coefficient or K-factor of about 5 and more preferably at least 4.9. The K-factor relates in part to the shape of the passageway22and other dimensions of the passageway22, inlet24and/or outlet26. As used herein, a discharge coefficient or K-factor of the sprinkler10is quantified or rated as a flow of water Q out of the passageway22of the body12of the sprinkler10in gallons per minute (gpm.) divided by the square root of the pressure p of water fed into body12in pounds per square inch gauge (psig), where K=Q/(p)1/2.

The sprinkler10is shown, in-part, in a non-actuated state, i.e., the outlet26is closed off by a closure assembly28. The closure assembly28is preferably disposed adjacent the outlet26to occlude the passage way22thereby preventing discharge of fluid from the outlet. The closure assembly28preferably includes a plug30coupled to a washer32having a perimeter contiguous to the inner surface20of the body12forming the outlet26. The washer32is preferably a Bellville type, Beryllium Nickel washer with a Teflon® coating, of about 0.02 inches. The plug30is preferably coupled to a seat member34by a compression screw or other fastener36.

The closure assembly further includes a thermally responsive trigger assembly or lever38providing means for controlling displacement of the washer32from the outlet26to operate the sprinkler10. More specifically, the lever38is preferably a fusible link assembly having two link halves held together by a solder link element40thereby maintaining the sprinkler10in a non-actuated state. When exposed to a sufficient level of heat, the solder element melts and the two link halves separate from one another so as to displace the closure assembly, operating the sprinkler10and permitting discharge of fluid from the outlet26. Alternative closure assemblies28and thermal triggers38can be provided so long as the alternative construction adequately occludes the passageway22when the sprinkler is in an non-actuated state and is adequately thermally responsive to actuate the sprinkler when needed. The trigger assembly38is preferably configured such that the sprinkler10has a temperature rating of ranging from about 135° F. to about 170° and more preferably is about 160° F. A higher sprinkler temperature rating can provide additional flexibility in sprinkler selection over a range of installation configurations and system designs.

Distal of the outlet26is the deflector assembly42providing means for distributing a fluid discharge from the outlet26over an area below the outlet. The deflector assembly42preferably includes a deflector plate assembly42a, one or more guide members42band an inner or guide member housing42cdisposed about a distal portion of the body12. InFIG. 2, the deflector assembly42is shown in both its non-deployed state (solid lines) and its deployed state (dashed lines). More specifically, the deflector assembly42has a first retracted position distal of the sprinkler outlet26and a second deployed position distal of the first position. Preferably, the plate18supports the deflector assembly42in its first position so as to locate at least the deflector plate assembly42aat a minimum distance from the outlet26.

In one preferred embodiment, the inner housing42cis disposed about a flange at the distal end27of body12. The inner housing42cpreferably extends coaxially within the outer housing14. The inner housing42cincludes an interior surface at least partially circumscribed about the longitudinal axis and to which one or more guide members42bare secured. Preferably, the deflector assembly42includes a pair of elongated guide members42bspaced parallel from one another about and extending distally along the direction of the longitudinal axis A-A preferably interior to the inner housing42c. Each of the guide members42bpreferably includes a proximal end coupled to a portion of the interior of the inner housing42c. Coupled to the distal ends of the guide members42bis the deflector plate assembly42a, thereby locating the deflector plate assembly42ain a first position distal of the outlet26. The guide members42bare preferably telescoping members relative to the inner housing42c, thus permitting the deflector plate assembly42ato extend distally from the first position to a second position distal of the first.

The deflector plate assembly42ais shown, in-part, in dashed line corresponding to the second or deployed position. In this preferred operational position, the deflector plate assembly42apresents an upper surface56and an opposite lower surface58, each substantially orthogonal to the longitudinal axis A-A for distributing a fluid discharge from the outlet26. In particular, the upper surface56provides a distribution surface for distributing a minimum flow rate discharged from the outlet26.

Operation of the sprinkler10provides that, upon exposure to a heat source, such as a fire, generating sufficient heat to melt the solder tabs52, the plate18falls away from the retaining sleeve48. The deflector assembly42then drops from its first or non-deployed position to a second or deployed position. The solder holding the fusible link38melts under the exposure to the increasing heat, the halves separate to actuate the sprinkler and displace the closure assembly. Upon displacement of the closure assembly, fluid discharges from the outlet26over the protection area.

Accordingly, the sprinkler10can be tested in accordance with UL 1626, Section 26 to identify an acceptable minimum operational flow rate of discharge from the sprinkler10capable of distributing a flow of fluid over a horizontal surface in a rectangular test area such as, for example schematically shown inFIG. 7C, such that the application rate or density for any one square foot area (1 ft.2) within the test area shall be at least 0.02 gallons per minute per square foot provided that no more that four-one square foot areas (4×1 ft2) in any given quadrant of the test area is at least 0.015 gallons per minute per square foot. More preferably, a preferred embodiment of the sprinkler10can be satisfactorily tested in accordance with UL 1626 so as to identify a minimum operational flow rate of thirteen gallons per minute (13 gpm) that results in a fluid distribution over a 256 square foot area (16 ft.×16 ft.) having a density of 0.05 gallons per minute per square foot (0.05 gpm/ft2). Even more preferably, the test is conducted so as to identify an actual minimum operating pressure for the preferred sprinkler10, having a nominal K-factor of 4.9 and a minimum operational flow of thirteen gallons per minute (13 gpm) capable of producing a fluid distribution over a 256 square foot test area (16 ft.×16 ft.) at a density of 0.05 gallons per minute per square foot (0.05 gpm/ft2), to be about seven pounds per square inch (7 psi.). Moreover, the preferred embodiment of the sprinkler10further provides for the minimal flow of seventeen gallons per minute (17 gpm) in successful fluid distribution tests for a 324 square feet area (18 ft.×18 ft.), and a minimal flow of twenty gallons per minute (20 gpm.) for a 400 square foot test area (20 ft.×20 ft.).

In addition, the sprinkler10can be tested in accordance with UL 1626, Section 27 to identify an acceptable level of fluid distribution from the sprinkler10capable of distributing a flow of fluid over a vertical surface in a rectangular test area such as, for example schematically shown inFIGS. 7A and 7B, such that walls within the test coverage area are wetted within twenty-eight inches (28 in.) of the ceiling with the sprinkler10discharging water in a uniform manner at a specified design flow rate. In a square coverage or test area each wall within the coverage area shall be wetted with at least five percent (5%) of the sprinkler flow. For rectangular coverage or test areas, each wall within the coverage area shall be wetted within a proportional water amount based on twenty percent (20%) of the total sprinkler discharge in accordance with the following formula:
WW=20%(D/P)
where:WW=Required amount of water collected on a wall in percentD=Wall length (ft.) andP=Total perimeter of coverage area (ft.)

It is believed that the various features of the sprinkler10and its operational components allow for compliance with UL 1626 at the minimal flow and pressures described above. The deflector plate assembly42aand the upper surface56preferably includes or defines one or more of surfaces substantially orthogonal to the longitudinal axis. More preferably, the deflector plate assembly42aincludes, as seen for example inFIG. 4B, a first centralized surface43spaced axially from the outlet26, a second surface45preferably circumscribing the first surface43and spaced distally from the first surface43. Even more preferably, the deflector plate assembly42aincludes a third surface47circumscribing the first and second surfaces43,45and spaced distally from the second surface45. The plurality of surfaces43,45,47provide a surface over which fluid discharged from outlet26can impact, deflect and flow for distribution beneath the sprinkler10.

One preferred embodiment of the deflector plate assembly42a, as seen inFIGS. 4A and 4Bpreferably includes the substantially flat plate member78and a projection member60. The flat plate member78and projection member60preferably collectively form the upper surface56and lower surface58of the deflector plate assembly42ato distribute the flow of fluid from the outlet26. For example, water discharged from the outlet26deflects off the surfaces of the flat plate member78and the projection member60to deflect the water axially and radially to further impact other elements of the sprinkler10such as the inner surface of the outer housing14, the inner housing42cand/or the guide members42bso as to provide a sprinkler performance and water distribution characteristic acceptable under UL 1626.

The projection member60is preferably centrally located with respect to the plate member78and aligned with the longitudinal axis A-A. As seen inFIGS. 4A,4B, the projection member60has a central core62having preferably a substantially planar proximal tip63and axially extending therefrom a substantially cylindrical body. The projection member60can include a member64extending radially from the core62. More preferably, diametrically disposed about the core62are radially extending members64. Alternatively, a plurality extending members can be radially disposed about the core62or further in the alternative, an enlarged flange can be circumscribed about the central core62. The projection member60preferably includes an oblique or angled surface66extending contiguously from the core62to the radially extending members64. The surface66can define an angle ranging from about twenty to thirty degrees (20°-30°) relative to the substantially planar surface and is more preferably about twenty-three degrees (23°) relative to the substantially planar surface. More preferably the projection member60is of integral or unitary construction in which the angled surface66is circumscribed about the longitudinal axis so as to define a substantially frusto-conical plane and further define a projection cone geometry. The planar tip63and radially extending members64respectively and preferably provide the first central surface43and the second surface45as described above.

The central core62of the projection member60is preferably engaged with the plate member78. More preferably, the plate member78preferably includes a central bore80disposed about the substantially cylindrical body of the core62. The plate member78preferably includes at least two lateral bores82aand82bdisposed about the central bore80. More preferably, the lateral bores82aand82bare aligned with and laterally spaced outside the radially extending members64as more clearly seen inFIG. 4A. The lateral bores82a,82bare preferably engaged or coupled to the preferred parallel guide members42bso as to centrally locate the deflector plate assembly42aalong the longitudinal axis A-A distal of the outlet26as seen inFIG. 2. More specifically, the guide members42bcan include pin elements preferably fixedly disposed within the lateral bores82a,82b. The radially extending members64and the adjacent pin elements of the guide members42bpreferably provides a fluid flow surface or channel therebetween to distribute a fluid flow toward the flow distributing features of the plate member78. The flow channels can provide for successful flow collection and wall wetting during UL 1626 testing. Referring again toFIG. 4A, the radially extending members64can include a void65defined at its lateral end adjacent to the guide member42cthrough which a fluid discharge can flow.

The plate member78is preferably substantially oblong or oval in shape, preferably substantially disposed in a plane substantially perpendicular to the longitudinal axis A-A and defined by orthogonal plate axes IVB-IVB and VIC-VIC, as seen in the plan view ofFIG. 4A. More specifically, the plate member78has a perimeter defining at least one arcuate edge84and one substantially straight edge86. Preferably, the plate member78has a perimeter defining two diametrically opposed arcuate edges84intersecting the major plate axis IVB-IVB and two substantially parallel straight edges86opposed about the major plate axis IVB-IVB and orthogonal to the minor plate axis VIC-VIC. Preferably, the maximum spacing between the two parallel straight edges86along the minor axis VIC-VIC ranges from about 1.1 inches to about 1.5 inches and is preferably about 1.25 inches.

In one preferred embodiment of the plate member78, a point along the defined arcuate edge84can further define a circle circumscribed about the longitudinal axis A-A. The defined straight edges86of the plate member78each further preferably define a chord length of the circle. Accordingly, the plate diameter defined by diametrically opposed points along arcuate edges84and merger axis IVB-IVB preferably ranges from about 1.25 inches to about 1.5 inches and is more preferably about 1.35 inches. Alternatively, the diameter defined by the plate member78can be a function of sprinkler height such the plate diameter to sprinkler height ratio ranges from about 0.5 to about 0.75 and is preferably about 0.70.

A preferred plate member78is shown inFIGS. 6A-6Dwithout the projection member60engaged therewith. The plate member78includes an upper surface78aand lower surface78beach preferably parallel to the plane defined by the intersection of the major axis IVB-IVB and the minor axis VIC-VIC. More preferably, at least one of the upper and lower surfaces78a,78bhas an angled portion, as seen for example inFIGS. 6C and 6D, that is angled at an angle α relative to the plane defined by the intersection of the major axis IVB-IVB and the minor axis VIC-VIC. The angle α can range from about five degrees to about ten degrees (5°-10°) and is more preferably about six degrees (6°). The angle α is preferably such that the lower surface is generally concave relative to the view from below the ceiling200. More preferably, the angled portion is disposed at the outer perimeter of the plate member78thereby providing the plate member78with an angled lip. Even more preferably, the angle α of the upper surface78aor the lower surface78bis provided for only a portion of the plate member78, for example, a radial span of about sixty degrees centered about the minor axis VIC-VIC. More specifically, the angled portion is preferably limited to the surface of the plate defining the diametrically opposed straight edges86. Thus preferably, two angled portions of the plate member78are diametrically spaced apart about the major axis IVB-IVB, and more preferably define bend lines79aand79b. The bend lines79aand79bare preferably diametrically spaced at about one inch from one another, or more alternatively are spaced at length equivalent to about eight-three percent (83%) of the straight edge to straight edge width.

The angled portions of the plate member78are preferably configured to provide compliance with the wall wetting requirements Section 27 of UL and 1626. Moreover of the angled portions of the plate member78are preferably configured to minimize water spray overthrow and thus provide compliance with operation cold-soldering test of Section 22 of UL 1626 where a first preferred sprinkler10is actuated adjacent to a unactuated second preferred sprinkler10located at about 8 feet from the actuated sprinkler10. Specifically, the straight edges86of the plate member78of the first sprinkler10can be spaced parallel the straight edge86in the plate member78of the second sprinkler10. To satisfy the requirements of the test, while the first sprinkler10is discharging fluid at 100 psig or more, the first sprinkler10cannot prevent the actuation of the second sprinkler10as the second sprinkler is being exposed to heat and flame, as provided for in Subsection 22.2 of UL 1626. At approximately 100 psig or greater, it is believed that the fluid flowing radially along the surfaces of the plate member78has sufficient velocity to produce a downward flow separation at the angled portion of the plate member78and straight edges86. Although the plate member78is preferably shown with the straight edges86and angular portion, any surface irregularity, geometry or treatment can be incorporated into the plate member78provided the surface irregularity can cause flow separation at fluid pressure of 100 psig or greater so as to prevent wetting of adjacent sprinklers located 8 or more feet in the directions of the plane defined by the A-A and IVB-IVB axes without the diminishing the effectiveness of the fluid distribution pattern provided by the deflector assembly42. Accordingly, the sprinkler10provides for a minimum sprinkler spacing of about eight feet. Maximum spacing between adjacent sprinkler is preferably equivalent to the length of the coverage area being covered by the sprinkler. Accordingly, where the sprinkler10is configured for a coverage areas of 16 ft.×16 ft., 18 ft.×18 ft., and 20 ft.×20 ft. the maximum spacing is respectively: 16 ft., 18 ft., and 20 ft.

Shown generally inFIG. 4Aand in greater detail inFIG. 6A, is the plate member78further including one or more slots88that define an opening or void extending from the upper surface78ato the lower surface78bto provide features for the distribution of a fluid flow. In addition, the slots88preferably initiate at the perimeter of the plate member78and extend radially toward the center of the plate member78to define a slot length Ls. Each of the slots88is preferably defined by a pair of spaced apart walls extending in the direction of slot elongation so as to define a slot width Ws. The slot to width ratio Ws:Lscan range from about 0.1 to about 0.15. The slot width Wscan vary along the length of the slot becoming wider or smaller at any portion of the slot along the slot length Ls. The walls defining the slots88can further taper relative to one or both of the upper and lower surfaces78a,78bor alternatively and more preferably be orthogonal to the upper and lower surfaces. Preferably, one or more of the slots88include a chamfer along at least a portion of at least one of the upper and lower surfaces78a,78b. The chamfers of sprinkler10can facilitate compliance with the flow collection requirements of the tests of UL 1626.

Any one of the slots88preferably includes a portion extending linearly so as to define a straight portion. The slot88can further include a non-linear portion, for example, defining a curve. More specifically, the spaced apart walls defining the slot88can curve along the slot length in a parallel fashion to define a curved slot. Alternatively, the walls defining the slot88can variably curve away and toward one another so as to substantially define an oblong shaped void in the plate member78. Preferably, a portion of the walls defining the slot88curve relative to one another so as to define a circular bore or void along the slot88. Accordingly, the slot88can be formed so as to include a linear portion and a non-linear portion in communication or continuous with the linear portion. Thus, the slot88can include a circular bore portion in communication with a straight portion. Moreover, the circular bore portion of the slot88can define a slot width that is greater than, or alternatively smaller than, the slot width of the straight portion. For example, as seen inFIG. 6A, a slot88can include a straight portion88ain communication with and terminating radially inward at tip defined by a circular bore portion88b. The circular bore portion88bcan include a countersink or alternatively include a counterbore. Moreover the slot88can include a series of portions of varying geometry along its slot length. For example, a preferred slot94, as seen for example inFIGS. 6A and 6D, can include a first straight portion94adefining a slot axis, a second circular bore portion94bhaving a center along the slot axis, and a third circular bore portion94chaving a center along the slot axis spaced from the center of the second circular bore portion94b. Circular bore portion94cpreferably has a smaller diameter than the second circular bore portion94b. Moreover, any one of circular bores94band94ccan include a countersink or a counterbore. Accordingly, the slot width Wscan vary along the slot length Lswhere, for example, the first straight portion94ahas a slot width, the second circular bore portion94bhas a second slot width greater than the first slot width and the third circular bore portion94chas a third slot width smaller than the slot widths of the first straight and second circular bore portions94a,94b.

The preferred plate member78includes one or more pairs of diametrically opposed slots88. More preferably, the plate member78includes one or more groups of diametrically opposed slots such as, for example, slot group90,92,94and96. Each of the group of slots90,92,94,96can vary from one another by varying any one of the previously described slot features. For example, the slot groups90,92,94,96can each have a slot length Lseach defining a ratio relative to the maximum radius of the plate member78. In one preferred embodiment of the plate member78, for example each of the first group of slots90defines a first ratio of about 0.25, each of the second group of slots92defining a second ratio of about 0.41, each of the third group of slots94defining a third ratio of about 0.23, and the fourth group of slots each defining a fourth ratio of about 0.29. Additional features may distinguish the groups of slots where for example, the third group of slots94includes a circular bore portion as described above. Any given group of slots is preferably periodically radially disposed about the plate member78. The angular spacing between slots can range from about 15° to about 120° depending upon the number slots in the group and/or the desired spacing relative to the major axis IVB-IVB and minor axis VIC-VIC. More preferably, the groups of slots are further evenly interposed among one another such that a slot of a one group and a slot of another group are angularly spaced apart by about fifteen degrees (15°).

The various components of the sprinkler10including the body12, the outer housing14, the cover plate assembly16, and the components of the deflector assembly can be made from any material capable of being machined, shaped, formed or fabricated provided the material can provide the requisite thermal responsiveness and fluid distribution characteristics. Preferably, materials for construction of the sprinkler components include brass, bronze, nickel, copper, steel, stainless steel or any combination thereof.

Accordingly, the preferred deflector plate assembly42aand its features as described above can, alone or in combination with the remainder of the deflector assembly42and/or the outer housing14can be part of the means for distributing fluid in a residential dwelling unit so that the sprinkler10is able to meet testing requirements of UL 1626. In the horizontal distribution test, UL 1626, Section 26 requires placing the selected sprinkler10over a protective area sub-divided into four quadrants with the sprinkler100placed in the center of the quadrants I-IV. A detailed layout of one quadrant is illustrated inFIG. 7C. In this quadrant, water collection pans are placed over the quadrant (e.g., quadrant III) of the protective area so that each square foot of the quadrant is covered by collector pan of one-square foot area. For pendent sprinklers, the top of the collector pan is eight feet below a generally flat ceiling of the test area, as seen for example inFIG. 7A. The coverage area CA is generally the product of a coverage width CW and length CL, as seen inFIG. 7C, and can be for example, 16 feet by 16 feet, 18 feet by 18 feet, or 20 feet by 20 feet. The length L of the quadrant III is generally the one-half the coverage length CL and the width W is generally one-half the coverage width CW, where each square foot of the quadrant is covered by collection pans of one-square foot area with the top of each collection being about eight feet below a generally flat ceiling of the coverage area and the amount of fluid collected is at least 0.02 gallons per minute per square foot for any of the collection pans except that no more than four collection pans for each quadrant receive at least 0.015 gallons per minute per square foot.

In accordance with the test, water or another suitable fire fighting fluid is supplied to the selected sprinkler10at a desired rate with the sprinkler10being tested via a one-inch internal diameter pipe with a T-fitting having an outlet at substantially the same internal diameter as the inlet24of the selected sprinkler100. The duration of the test is twenty-minutes and at the completion of the test, the water collected by the collection pan CP (as delineated by the square like grid) is measured to determine if the amount deposited complies with the minimum density requirement for each coverage area.

As promulgated by Section 27 of UL 1626, a vertical fluid distribution test provides for an arrangement to determine the vertical fluid distribution of any sprinkler suitable for the protection of a dwelling unit. In the test arrangement for the residential pendent sprinkler100, the sprinkler100is placed over a center of a coverage area CA at one-half the coverage length CL or width CW (FIGS. 7A and 7B) of the coverage area. A suitable fire-fighting fluid such as water is delivered to the sprinkler10at a specified flow rate with the sprinkler10being tested via a one-inch internal diameter pipe. Water collection pans of one-square foot area are placed on the floor against the walls of the test area so that the top of the pan is six feet, ten inches below a nominally eight feet height H generally flat ceiling. The duration of the test is ten minutes at which point the walls within the coverage area should be wetted to within 28 inches of the ceiling at the specified design flow rate. Where the coverage area is square, each of the four walls must be wetted with at least five percent of the sprinkler flow. Where the coverage area is rectangular, each of the four walls must be wetted with a proportional water amount collected that is generally equal to 20 percent times a total discharge of the sprinkler10at the rated flow rate of the residential fire sprinkler times the length of the wall divided by the perimeter of coverage area CA.

As utilized in this test, the deflector assembly42including the slots88of the plate member78is believed to allow the break up of the flow stream extending from the outlet26perpendicular to the frame arms14in order to meet a maximum 20-foot spacing between sprinklers in the operational test of Section 22 of UL 1626. The preferred plate member78in combination with the projection member60is believed to provide for a sufficient fluid distribution over the test coverage area perpendicular to the longitudinal axis A-A. Further, it is believed that the features described above in relation to the deflector assembly42allows the sprinkler10to provide an operating flow rate of thirteen gallons per minute (13 gpm) of water at an operating pressure of about seven pounds per square inch gauge (7 psig.) fed to the inlet26so that a density of at least 0.05 gpm/ft2of fluid is provided to a coverage area of 16 feet by 16 feet under at least the horizontal distribution test of UL 1626.

Moreover, the above described features provide a sprinkler performance in the preferred sprinkler10having a minimal operating flow of seventeen gallons per minute (17 gpm) in a successful fluid distribution and fire tests for a 324 square feet area (18 ft.×18 ft.), and a minimal operating flow of twenty gallons per minute (20 gpm) for a 400 square foot test area (20 ft.×20 ft.). More preferably, the sprinkler10can provide a minimal flow of seventeen gallons per minute (17 gpm) in successful fluid distribution and fire tests for a 324 square feet area (18 ft.×18 ft.) at an operating pressure of about twelve pounds per square inch (12 psi.), and further provide a minimal flow of twenty gallons per minute (20 gpm.) for a 400 square foot test area (20 ft.×20 ft.) at less than seventeen pounds per square inch and even more preferably at an operating pressure of about 16.7 psi.

Besides the above described fluid distribution tests, actual fire tests can also be performed in accordance with Section 28 of UL 1626 for the preferred embodiments. In particular, a fire test can be performed with sprinkler10to limit the temperature in a location of the test area so as to satisfy the criteria of Section 28.1 of UL 1626. More specifically, a test area can be constructed with the preferred sprinklers10installed in accordance with Section 28.2 of UL 1626. Actual fire tests conducted with sprinkler10can limit temperatures for each rated spacing as specified by the installation requirements having no more than two sprinklers10operate, such that: (i) the maximum temperature three inches below the ceiling at the tested locations does not exceed 600° F. (316° C.); (ii) the maximum temperature five and one-quarter feet (5¼ ft.) above the floor shall not exceed 200° F. nor exceed 130° F. for more than any continuous two minute period; and (iii) the maximum ceiling temperature ¼ inch behind the finished ceiling surface shall not exceed 500° F. (260° C.).

As a preferably concealed pendent sprinkler, the sprinkler10provides for as much vertical adjustment ranging from about ¼ inch to about ¾ inch and preferably about ½ inch when installing the sprinkler in a sprinkler system100relative to a fixed pipe drop. This vertical adjustment can reduce the accuracy to which fixed pipe drops of system100must be cut to ensure a proper installation.

Finally, because the preferred embodiments of the sprinkler100are able to pass all of the performance tests required by UL 1626, the preferred embodiments are able to be listed by a listing authority, such as, for example, UL, for design and installation as a residential fire sprinkler, as defined in Section 3.6.2.10 of NFPA 13. The above described features of the preferred embodiment of the sprinkler10can, in a residential fire protection system, as per NFPA 13, 13D and 13R, provide an optimized fire protection at lower minimum design pressures for design protection area of 144 square feet or greater. Consequently, at least the deflector assembly42alone or in combination with the other operational components of the sprinkler10, preferably provides the means for distributing fluid over a coverage area of a residential dwelling unit. Thus, the sprinkler10can be installed in a preferably wet residential sprinkler system in accordance with the NFPA Standards to provide a suitable fluid density over a maximum coverage area of 256 square feet or less in which the sprinkler10has a minimum discharge flow rate of about thirteen gallons per minute (13 gpm) and a minimum design or an operating pressure of about seven pounds per square inch delivered to the sprinkler. In addition, the preferred sprinkler10can be installed in a residential sprinkler system for a maximum coverage area of about 324 square feet, given that the sprinkler10can deliver a minimum flow rate of about seventeen gallons per minute (17 gpm) at a minimum design pressure of about twelve pounds per square inch (12 psi) and further provide for a maximum coverage area of about four hundred square feet (400 ft.2) given that the sprinkler10can deliver a minimum flow rate of about twenty gallons per minute (20 gpm) at a minimum design pressure of about seventeen pounds per square inch (17 psi). More specifically, with the lower minimum operating design pressures, the preferred embodiments can be utilized in the design of fire protection system for coverage area of 324 square feet or greater at approximately a fifteen percent lower design pressure than known residential fire sprinklers. Accordingly, the sprinkler10provides a preferred device and method for protecting a coverage area that can range from about 144 square feet to about 400 square feet by introducing a fire fighting fluid to the sprinkler body12at a minimum operating pressure ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi). The preferred device and method further provide for discharging the fluid from the sprinkler body12at a flow rate ranging from about thirteen gallons per minute to about 20 gallons per minute (13-20 gpm) and distributing the fluid over the coverage area at a density of about 0.05 gallons per minute per square foot (0.05 gpm/ft2).

One preferred embodiment of the sprinkler10is shown and described inTyco Fire&Building Product Data Sheet Series LFII Residential Concealed Pendent Sprinklers, Flat Plate4.9K(January 2006) which is incorporated in its entirety herein by reference thereto. Shown below is a tabulated summary of the minimum flow and residual pressures for the preferred sprinkler having a 160° F. (71° C.) temperature rating for various coverage areas. In addition, the preferred sprinkler can provide for a maximum working pressure of about 175 pounds per square inch (175 psi.)

Table 1 provides for various maximum coverage areas for the preferred sprinkler10and further provides preferred minimal flow rates and operating fluid pressure. The provided minimal flow rates and operating pressures can also be used for a sprinkler10used to protect a coverage area having dimensions less than or between those indicated so as to ensure adequate distribution density for the actual coverage area.