BACKGROUND OF THE INVENTION 1. Field of the Invention [002] The present invention relates generally to fire suppression systems and, in particular, to a fire suppression system for protecting a structure from exterior fire threats.

2. Description of the Related Art [003] Structures, such as houses and office buildings, are sometimes faced with the threat of fire. Many structures are protected from internal fires through an interior fire suppression system, such as an interior sprinkler system. Structures are often left unprotected, however, from exterior fire threats such as radiant heat generated from a fire in a neighboring structure or burning embers that are blown onto the structure from a nearby fire.

[004] When a residential neighborhood is faced with an impending fire, the resources available to local firefighters are limited, and homeowners often take additional measures to protect their houses and yards. For example, a homeowner may climb onto the roof of the house with an ordinary garden hose or lawn sprinkler to fight the impending fire. This approach is usually inadequate to protect the house and dangerous to the homeowner. A typical lawn sprinkler sprays water up into the air to cover a large section of the lawn. The windy conditions that often accompany a wildfire are likely to carry much of the water from a lawn sprinkler away from both the house and yard. A garden hose requires constant operation by the homeowner who must stay on the roof to direct the water towards various sections of house's exterior. While operating the garden hose, the homeowner will often face an impending fire, thick smoke and high winds, which could result in the homeowner being seriously injured or killed from the heat, smoke inhalation or a fall from the roof. In an emergency situation, the homeowner should be focused on personal safety. The use of a lawn sprinkler and garden hose requires constant operation and places the homeowner in greater danger.

[005] Another impediment to the homeowner's use of a garden hose or lawn sprinkler is the reduced availability of water during emergency situations. In many geographical areas, the water pressure available to a structure is reduced during a fire emergency to provide emergency personnel with the water pressure they need to fight the fire.

[006] Prior attempts to create an exterior fire suppression system have proven to be impractical. For example, U. S. Patent No. 3,576, 212, entitled"FIRE-SHIELDING <BR> <BR> DEVICE, "which issued on April 27,1971, describes a system in which four structures are installed adjacent to each of four exterior walls of a building. Each structure extends from the ground to a height above the roof of the building and includes a pipe that is connected to a water source at the bottom of the structure. At the top of each structure is a pair of sprinkler heads, one designed to spray water in a horizontal direction and another designed to spray water in a high arc to be spread over the roof by the wind.

[007] Another approach is described in U. S. Patent No. 5,263, 543, entitled "EXTERNAL FIRE PREVENTION SYSTEM,"which issued on November 23, 1993. In this patent a water pipe is run up the side of the building and connected to another pipe that lies across the top of the roof. The second pipe includes a plurality of sprinklers that are spaced apart. A smoke detector is placed on the side of the building to detect an approaching fire and automatically activate and deactivate the external fire prevention system.

[008] These and other prior art approaches suffer from many drawbacks that have prevented the widespread implementation of exterior fire suppression systems. For example, these systems are not aesthetically pleasing and once installed would be considered an eyesore in many communities. The pipes are exposed to the environment, which can lead to corrosion making the system not only unsightly, but also unreliable. In addition, many homes and other structures are designed with roofs having various shapes and slopes that are not contemplated by these limited systems.

Many of the prior art systems also waste water by directing water up into the wind and do not account for the reduced water pressure that is available during a fire emergency.

[009] Some cooling or fire suppression systems make use of a ridge-mounted water line to dispense water on the roof of a structure. However, prior-art systems are unsightly, subject to corrosion, and/or lacking in reliability and wetting ability.

Consequently, ridge-mounted sprinklers are not generally used for fire suppression, and most houses remain unprotected by them, even in fire-prone areas.

[010] In view of the drawbacks in the prior art, there is a need for an improved exterior fire suppression system. It would be desirable for the system to be aesthetically pleasing and capable of effectively saturating the structure's exterior using the water pressure that is available to the structure during a fire emergency. It would further be desirable for the system to be easy to operate without endangering the safety of the occupants and firefighters, and inexpensive to install or retrofit into existing structures of various sizes and shapes. It is further desirable to provide a ridge-mounted sprinkler line that can be economically retro-fitted to an existing roof structure in an aesthetically pleasing way. The ridge-mounted sprinkler line should be able to withstand a harsh exterior rooftop environment, without sacrificing fire suppression performance, appearance, and reliability.

SUMMARY OF THE INVENTION [011] The present invention is an exterior fire suppression system, and method for installation thereof, that overcomes many of the drawbacks found in the prior art systems. In a preferred embodiment, an exterior fire suppression system includes at least one sprinkler that is connected to a water supply of a structure or a secondary water source. The sprinkler is mounted within the structure and is substantially hidden from view when the system is inactive. When activated, the sprinkler saturates a portion of the structure's exterior, providing the structure with protection from external fire threats.

[012] The sprinkler is preferably connected to the structure's water supply through a plumbing system, which includes a gate valve for controlling the flow of water to the sprinkler. The plumbing system may tap into the structure's water supply at any location that provides sufficient water pressure to operate the sprinkler, such as through pipes in an attic or through the main water line on the exterior of the structure. The gate valve preferably includes both mechanical and electrical controls. The gate valve may be located at any point between the water line and the sprinkler, but is preferably installed adjacent to the strudure's eSerior to provide firefighters ana other indiviatuals with access to the fire suppression system.

[013] A fire suppression system according to the invention comprises one or more roof sprinklers adapted to saturate a portion of the roof when the fire suppression system is activated. Each roof sprinkler is preferabtyjsonceaied by a facade or other structure that aesthetically matches the structure's roof or elements typically Xo ! und on the structure's roof. Sprinklers for use with the system may be configured in various different ways. In an embodiment of the invention, the system includes fixed sprinkler heads concealed under a second layer of roofing material along a ridge line. The fixed sprinkler heads may comprise nozzles spaced at intervals along a water line, such as a copper pipe running along the ridge line. The water line may be covered by roofing materials, for example, a prefabricated ridge piece, that conceals the line for aesthetic purposes, and protects it from the elements. The nozzles may protrude through access holes cut into the roofing materials, and may be configured to spray water onto the roof on both sides of the ridge line. The nozzles may comprise relatively small metal nozzles (for example, less than one inch high) that are not readily visible from the ground level. Such sprinklers may be configured such that a casual observer will not detect their presence, or anything else unusual about the roof structure. The invention thus provides a superior ridge-mounted sprinkler set, with a novel structure that overcomes the limitations of the prior art.

[014] In the alternative, or in addition, a fire suppression system according to the invention may include popup sprinklers. Popup sprinklers may be especially useful for wetting roof areas that are difficult to reach using concealed fixed-head sprinklers, such as areas that cannot be wetted by flow from a ridge line. To cover such areas, the roof sprinkler may comprise a popup sprinkler that is disguised as a standard roof vent when inactive, and that extends beyond the top of the vent facade when activated to spray water onto a portion of the roof.

[015] In the alternative, or in addition, one or more popup-type roof sprinklers may be installed in a sprinkler box below the roofline. The sprinkler box may include a bottom portion and a top portion. The bottom portion may include water-tight floor having a drain at the bottom thereof and at least one side having a hole adapted for receiving a water pipe. The bottom portion may be installed under the roof adjacent to the roofline, such as by attachment to roof beams or other available supports. The roof sprinkler is disposed inside the bottom portion and is connected to the plumbing system of the fire suppression system through the water pipe. In one embodiment, a pressure regulator, a pressure gauge and a shut-off valve are installed inside the bottom portion between the roof sprinkler and the water pipe.

[016] The top portion may be adapted to substantially enclose the roof sprinkler inside the sprinkler box. In a preferred embodiment, the top portion is a flashing kit that inserts into the bottom portion. The shape of the top portion is adapted to substantially match the shape and angle of the adjacent roofline and, after installation, may be covered with the structure's standard roofing material. The top portion may include a hole and a cap.

The cap plugs the hole when the fire suppression system is inactive, inhibiting water and debris from entering the sprinkler box. When the system is activated, the popup sprinkler lifts or ejects the cap and extends through the hole (and a corresponding hole in the roofing material if necessary) to direct water onto the surface of the roof.

[017] The sprinkler box may include at least one access panel, providing access to the interior components of the sprinkler box for installation and maintenance. In one embodiment, the access panel is a lid located on the top portion of the sprinkler box that is accessible under the roofing material. In an alternative embodiment, the access panel comprises a door on a side of the bottom portion of the sprinkler box that is accessible from the interior of the structure (e. g. , an attic).

[018] A roof sprinkler according to the invention may include a housing and a sprinkler head assembly. The housing may comprise an outer pipe having a bottom adapted for connection to the plumbing system and a top that is enclosed by a cap. The cap may include a hole adapted to slidably receive the sprinkler head assembly. The sprinkler head assembly may include an inner pipe that is inserted through the hole in the housing cap such that a first end of the inner pipe is located within the housing and a second end of the inner pipe is located outside of the housing. The first end may include a pair of flanges extending from the outer surface of the inner pipe to the inner surface of the housing. The sprinkler head may be attached to the second end of the inner pipe and includes at least one opening adapted to direct water towards a portion of the roof. The roof sprinkler is preferably constructed of a material that provides protection from corrosion, for example, stainless steel, bronze, or heat and UV-resistant plastics.

[019] When inactive, the sprinkler head assembly lowers down through the hole by gravity until the sprinkler head rests on the cap of the housing. When water flows into the housing from the plumbing system, the water pressure against the first flange pushes the sprinkler head assembly upward until the second flange engages the cap.

Fully extended, water flows into the first end of the inner pipe, out the second end of the inner pipe and into the sprinkler head, which directs the water flow downward through the openings towards the roof.

[020] The fire suppression system may further include one or more eave sprinklers adapted to saturate a portion of an exterior wall of the structure when activated. The eave sprinkler may be installed under an eave of the structure, substantially hidden from view. The eave sprinkler may comprise a perforated pipe running across the eave. The pipe may be configured to spray water against or alongside an exterior wall of the structure. Alternatively, the eave sprinkler may include a plurality of sprinkler heads to control the spray of the water. The eave sprinkler may be activated by at least one heat sensor that is disposed adjacent to the eave sprinkler and is electrically connected to the automatic gate valve of the plumbing system. The heat sensor is adapted to activate the flow of water through the gate valve when the heat sensor detects a temperature that is higher than a predetermined threshold value.

[021] In one embodiment, the automatic gate valve is connected to an electronic control panel for activating and deactivating the system electronically. The electronic control panel may be a dedicated control panel used only for the exterior fire suppression system or may be connected to other systems in the structure, such as an interior fire suppression system, a security system or a home computer network. In a preferred embodiment, the electronic control panel provides for remote activation of the fire suppression system through a monitoring service, telephone, remote control, computer network or other instrumentality. Heat sensors, smoke detectors or other sensing devices may be connected to the electronic control panel to activate the fire suppression system automatically.

[022] The plumbing system may also include a flow switch, a breather valve and a mixing valve. The flow switch may be adapted to detect the flow of water through the plumbing system and instruct the electronic control panel to produce an audible alarm to warn occupants of an impending fire. The flow switch and electronic control panel may also be adapted to provide the user with notification of a leak in the fire suppression system. The breather valve is installed between the gate valve and the sprinkler, and may be used to drain residual water from the plumbing system when the system is inactive. The mixing valve may be installed to add a mixing agent to the water for better fire suppression qualities. For example, the fire suppression system may be adapted to produce a fire retardant foam or gel.

[023] An installed fire suppression system preferably includes a system of roof sprinklers and eave sprinklers that operate together to completely saturate critical exterior areas of the structure when activated. Roof sprinklers are preferably arranged to provide complete saturation of the roof when the system is activated. Saturation of any given portion of the roof may be achieved directly from a roof sprinkler or indirectly through water runoff from the activated system. For example, the roof sprinklers may be adapted to direct water from and/or towards the highest point of a sloped roof, while lower portions of the roof are saturated as the sprayed water flows down the roof. It is contemplated that the eave sprinklers may be controlled through the same plumbing system as the roof sprinklers or may be separately controlled through their own plumbing system.

[024] A more complete understanding of the exterior fire suppression system and method for installation will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of preferred embodiments. Reference will be made to the appended sheets of drawings, which will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS [025] The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings described below, in which like reference characters are used to identify like items throughout.

[026] Fig. 1 is a block diagram of a structure's exterior in accordance with a preferred embodiment of the present invention.

[027] Fig. 2 is a block diagram of an exterior fire suppression system installed in the structure in accordance with a preferred embodiment of the present invention.

[028] Fig. 3 is a block diagram of activated roof sprinklers in accordance with a preferred embodiment of the present invention.

[029] Fig. 4A is a cut-away perspective view showing a ridge-mounted sprinkler line comprising a row of fixed nozzles protruding through roofing materials that conceal a water line running along a roof ridge line. Fig. 4B shows a cross-sectional view of the ridge-mounted sprinkler line.

[030] Figs. 5A and 5B are block diagrams illustrating an inactive popup sprinkler and a disassembled popup sprinkler, respectively, in a roof vent accordance with a preferred embodiment of the present invention.

[031] Figs. 6A and 6B are block diagrams illustrating an inactive popup sprinkler and activated popup sprinkler, respectively, in accordance with a preferred embodiment of the present invention.

[032] Figs. 7A and 7B are block diagrams of a sprinkler box providing a perspective view and side view, respectively, in accordance with a preferred embodiment of the present invention.

[033] Fig. 8 is a block diagram illustrating a top view of the contents of a sprinkler box in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [034] A preferred embodiment of the present invention will now be described.

Referring to Fig. 1, an exemplary structure equipped with an exterior fire suppression system is illustrated. A house 10 includes common functional and aesthetic exterior features including a roof having a plurality of roofing tiles 12, a roof vent 14, a roof ridge piece 44 and exterior walls 16. A main water pipe 18 provides water to the house 10 from a pressurized water source such as a public water supply. In alternative embodiments, the water may be pumped into the fire suppression system from a fixed water source (e. g., a pool, pond or storage tank) or a from a mobile water source such as a fire engine. Although a preferred embodiment of the present invention will be described with reference to the house 10, it will be appreciated by those having ordinary skill in the art that the exterior fire suppression system can be installed into other structures having other combinations of functional and aesthetic exterior features. For example, the structure may include any roof design, such as a flat roof or domed roof.

[035] A preferred embodiment of an exterior fire suppression system will now be described with reference to Fig. 2. An exterior fire suppression system includes at least one sprinkler, such as roof sprinklers 30,32 and 47 and eave sprinklers 34 and 36, that is connected to the water supply 18 of the structure 10 through a plumbing system 40.

The sprinklers are mounted onto or within the structure 10 and are disguised as standard structural elements, or otherwise substantially hidden from view, when the system is inactive. When activated, each sprinkler saturates a portion of the structure's exterior to protect the structure from external threats of fire and radiant heat.

[036] The plumbing system 40 includes at least one pipe 40a and at least one gate valve 42 for controlling the flow of water to the sprinklers. The pipe 40a is installed on the interior of the structure between the gate valve 42 and the sprinkler to provide water to the sprinkler when the gate valve is in an"on"position. In a preferred embodiment the plumbing is standard % inch copper piping, but other plumbing may also be used, such as interior pipes commonly used for plumbing or interior fire suppression systems.

Optionally, copper pipe may be joined using conventional solder and/or using crimped o-ring coupling such as sold under the trademark"ProPress"by the Ridge Tool Co. of Elyria, Ohio.

[037] The plumbing system 40 may tap into the water supply 18 at any location on the exterior or interior of the structure 10 that provides adequate water pressure to operate the fire suppression system and from which plumbing can be installed and connected to the sprinklers. For example, the plumbing system 40 may tap into the water supply 18 in a garage or attic of the structure 10 or through an interior fire suppression system that is installed in the structure 10. The fire suppression system may be adapted to operate at 30 psi or one half of the water pressure typically supplied to the structure, whichever is greater. In many areas, water systems are expected to supply at least half of normal water pressure in the event of fire. Thus, sprinkler nozzles may be designed for optimal operation at less than normal water pressure, and one or more pressure reduction valves may be used to reduce water pressure when the water supply exceeds the design pressure. In alternative embodiments, the fire suppression system may be adapted to operate at other water pressures depending on various factors, for example, the configuration of the fire suppression system, the water supply, the size of the structure, the material being delivered through the system (e. g. , foam or gel) and the level of the threat of fire.

[038] The gate valve 42 may be located at any point between the water supply 18 and the sprinklers 30,32, 34,36 and 47, but is preferably installed adjacent to the structure's exterior with a manual control to provide access to the fire suppression system by firefighters and other individuals. Although any type of valve that is capable of controlling the flow of water through the plumbing system 40 may be used, the gate valve 42 preferably includes both mechanical and electrical controls.

[039] The fire suppression system may include at least one eave sprinkler 34 and 36 that is adapted to saturate a portion of an exterior wall 16 of the structure 10 when activated. Each eave sprinkler 34 and 36 may be installed on the underside of an eave 38, substantially hidden from view. In one embodiment, each eave sprinkler 34 and 36 includes a 3/4 inch (or larger) pipe running parallel to an eave, and includes a plurality of holes or nozzles adapted to spray a sheet of water onto and along the exterior wall 16 of the structure 10 to protect the exterior walls 16 from radiant heat.

[040] In alternative embodiments, the eave sprinklers 34 and 36 may include sprinklers directed at the exterior walls 16 or directed downward, or both in alternation. It may be advantageous to thread brass nozzles directly into threaded holes formed at intervals along the length of a piece of tubing or pipe, such as, for example, a length of copper tubing. Suitable brass nozzles may be configured to disperse an adequate volume of water when the system is operated at its design water pressure. In an embodiment of the invention, round-orifice, wide angle spray, 1/8 NPT brass nozzles were used, available from Spraying Systems Co. of Wheaton, Illinois. The nozzles had a capacity of about 1 to 2 gallons per minute at a supply pressure of about 15 to 40 psi. Other nozzles may also be suitable, depending in system design.

[041] Depending on the structure of the eaves, the eave sprinklers 34 and 36 may be visible from directly underneath the eaves 38. To improve the aesthetic appearance, the eaves can be boxed to hide the eave sprinklers 34 and 36 within the eaves. In addition, or in the alternative, the water line may be passed through aligned through- holes in the rafters under the eaves, parallel to the exterior wall. The eave sprinklers 34 and 36 may be controlled through the same plumbing system as the roof sprinklers 30 and 32 or may be separately controlled through their own plumbing system.

[042] The fire suppression system further includes at least one roof sprinkler 30,32, 47. Referring to Fig. 3, each roof sprinkler 30,32 and 47 is adapted to saturate a portion of the roof 12a and 12b, respectively, when the system is activated. Roof sprinklers are substantially concealed from view and covered, both for aesthetic reasons and for protection from the exterior environment. Roof sprinklers, such as sprinkler 32, may be concealed by a façade on the roof 12 or by other elements of the roof. Roof sprinklers 30 and 47 may be mounted underneath and substantially concealed by roofing materials used to cover roof 12.

[043] Economical coverage of large roof areas may often be accomplished using a water line 46 mounted along the ridge line, as shown in Figs. 4A and 4B. The ridge- mounted line 46 may be adapted to feed a plurality of sprinkler nozzles 47 configured to deliver a spray of water downward from the ridge line. In an embodiment of the invention, nozzles 47 may comprise brass nozzles as described above for eave sprinklers, tapped directly into copper line 46. Line 46 may be connected to the water supply system through any suitable fitting and/or line passing through an opening in the roof into the interior of the structure. The opening may be sealed with a flashing compound or any suitable roof sealant, and covered by roofing material 45, thereby preventing moisture egress. Roofing material 45 may comprise individual ridge pieces or a single prefabricated pieces as available for many roofing materials, such as composite shingles. Holes should be cut through the ridge roofing material 45 to accommodate the nozzles 47 protruding upwards from line 46. Then, the roofing material 45 may be laid over line 46 and fastened in any suitable manner to the roof.

Material 45 may thus be used to both cover line 46 and hold it in place. In the alternative, or in addition, line 46 may be secured to the roof at the ridge line using any suitable retainers or fasteners.

[044] As thus configured, ridge line 44 provides a row of unobtrusive sprinkler nozles right along the crest of the roof. The nozzles may be positioned just above the roofing material 45, protruding only a short distance above it. For example, the nozzles may protrude less than an inch above the roofing materials. To the casual observer on the ground, such nozzles may be nearly unnoticeable, or completely unnoticeable. The nozzles should be configured to spray water in a continuous pattern along the ridge line, using droplets that are sufficiently large to avoid being carried away by wind. When the nozzles are supplied with water pressure, water is thereby spread evenly along the crest of the roof, from whence it runs down gradient, wetting the entire roof.

[045] In addition, or in the alternative, the fire suppression system may include one or more popup sprinklers 30,32. Popup sprinklers tend to be more complex and more expensive than fixed nozzles, but may provide better coverage for certain roof areas that are difficult to wet from the ridge line. Such areas may include, for example, areas beneath gables or overhangs, low gradient (flat) areas, and corners.

[046] Popup sprinklers may be configured in various different ways. For example, roof sprinkler 32 is a popup sprinkler disguised as a standard plumbing roof vent 14. As illustrated in Fig. 3 and Figs. 5A and 5B, the roof sprinkler 32 extends beyond the top of the vent façade 14 when activated to spray water 39a onto a portion of the roof 12a.

The vent façade 14 may be part of a standard vent flashing 15 that is installed into the roof as known in the art. To prevent water from leaking into the interior of the structure through the vent flashing 15 when the sprinkler 32 is activated, the gaps between the sprinkler assembly and the interior of the vent fagade are preferably sealed using a caulk.

[047] In addition, or in the alternative, roof sprinklers may be configured as popup sprinklers 30,32 in a concealed location, such as installed in a sprinkler box 36 that is located underneath the roof 12, or in a vent facade 14. When activated, the roof sprinklers 30, 32 extend beyond the top of the sprinkler box 36 or vent fagade 14 to spray water 39b onto a portion of the roof 12b. Each roof sprinkler 30 and 32 is preferably adapted to spray water downward towards the roof 12 to reduce the amount of sprayed water that is carried away by the wind. In an alternative embodiment, the roof sprinklers may be adapted to deliver fire retardant foam or gel onto the structure.

[048] Referring to Figs. 5B, 6A and 6B, a preferred embodiment of a popup roof sprinkler 32 will now be described. In Fig. 6A the popup roof sprinkler 32 is illustrated in an inactive state. In Fig. 6B, the popup roof sprinkler 32 is illustrated in an activated state. The roof sprinkler 32 includes a housing 52 and a sprinkler head assembly 54.

The housing 52 includes an outer pipe having a first end 56 adapted for connection to the plumbing system and a second end 58 which is capped. First end 56 may include threading on the interior of the housing 52 that corresponds with threading on a pipe of the plumbing system. The capped end 58 may include a hole 60 adapted to slidably receive the sprinkler head assembly 54. The sprinkler head assembly 54 may include an inner pipe 55 that is inserted through the hole 60 in the housing 52 such that a first end 62 of the inner pipe 55 is located within the housing 52 and a second end 64 is located outside of the housing 52. Inner pipe 55 may be approximately 12-15 inches in length, or any other suitable length. The first end 62 includes a pair of flanges 66a and 66b extending from the outer surface of the inner pipe 55 to the inner surface of the housing 52.

[049] The sprinkler head assembly 54 may also include a sprinkler head 68 having a diameter that is wider than the hole 60 and which is attached to the second end 64 of the inner pipe 55. In an embodiment of the invention, the second end 64 of the inner pipe 55 may include a groove 65 around its circumference adapted to receive an O-ring 67, and the sprinkler head 68 may include a corresponding groove (not shown) in its interior surface. The sprinkler head assembly 54 may be assembled by pushing the sprinkler head 68 down over the second end 64 of the inner pipe 55, creating a water- tight seal between the O-ring 67, the groove 65 and the interior of the sprinkler head 68.

The inner pipe 55 may also include at least one recess 57 for receiving a corresponding screw 69 to secure the sprinkler head 68 to the inner pipe 55 and prevent its rotation. In the alternative, the sprinkler head and inner pipe may include corresponding threading allowing the sprinkler head to be screwed onto the inner pipe.

[050] When inactive (Fig. 6A), the sprinkler head assembly 54 is pulled down through the hole 60 and into the housing 52 by gravity until the sprinkler head 68 rests on the second end 58 of the housing 52. When water flows into the housing 52 through the first end 56, the water pressure creates an upward pressure on the flange 66b causing the sprinkler head assembly 54 to move upward through the housing 52 until the flange 66a engages the capped second end 58 of the housing 52. Fully extended, water continues to flow into the first end 62 of the sprinkler head assembly 54, out the second end 64 and into the sprinkler head 68, which directs the water downward towards the roof through at least one opening 70 in the sprinkler head 68. The-spray pattern produced by the sprinkler 50 may be adjusted to form a desired spray pattern by modifying the size, shape and number of openings 70 in the sprinkler head 68. The inner pipe 55 may also include a groove 72 extending across a portion of its length. A screw or pin 74 may be inserted through the housing 52 and into the groove 72 to prevent the sprinkler head assembly 54 from rotating during operation. The roof sprinkler 32 should be constructed of a material that provides protection from corrosion and resistance to heat, such as stainless steel, bronze, and/or heat and UV-resistant plastics.

[051] Referring to Figs. 7A and 7B, an embodiment of a sprinkler box 100 will now be described. The sprinkler box 100 includes a bottom portion 102 and a top portion 104.

The sprinkler box 100 may be constructed from copper or other sheet metals, or plastic.

The bottom portion 100 is installed below the roofline of the structure, preferably by attaching the bottom portion 102 to rafters 106 of the structure via a plurality of screws 108. In an embodiment, the bottom portion 102 is adapted to fit between the rafters of an attic of a standard structure. For example, bottom portion 102 may be approximately 14. 5 inches long, 12 inches wide and 19-24 inches deep. To prevent water from reaching the interior of the structure during operation, the sprinkler box 100 may comprise a liquid-tight enclosure having lower surface 120 drained by at least one drain 122. The drain 122 may be connected to the plumbing of the structure to remove the water that enters the box.

[052] Top portion 104 of the sprinkler box 100 may comprise a flashing kit that fits inside a previously installed bottom portion 102. The top portion 104 may be adapted to substantially enclose the roof sprinkler inside the sprinkler box 100. In a preferred embodiment, top portion 104 may comprise a flashing kit that slidably inserts into the bottom portion 102. The shape of the top portion 104 may be adapted to substantially match the shape and angle of the adjacent roofline and, after installation, may be covered with the structure's standard roofing material. Advantageously, different top portions may be configured for use with the same sprinkler box, to accommodate different roof configurations during installation.

[053] Top portion 104 may also include a hole 126 and a cap 128. The cap 128 plugs the hole 126 when the fire suppression system is inactive, inhibiting water and debris from entering the sprinkler box 100. When the system is activated, the popup sprinkler lifts or ejects the cap 128 and extends through the hole 126 (and a corresponding hole in the roofing material) to direct water onto the surface of the roof. The cap 128 may be attached to the sprinkler box 100, such as through a chain or string or via a springed hinge adapted to close the cap 128 into the hole when the system is inactive. In the alternative, cap 128 may be attached to an upper surface of the sprinkler head.

[054] The sprinkler box 100 may include at least one opening that provides a user with access to the contents of the sprinkler box 100 for maintenance or adjustment of the popup sprinkler 110 and associated plumbing. In a preferred embodiment, access to the components of the sprinkler box is provided through a hole 130 cut into the top portion 104. Along the edge of the hole 130 is a lip 132 that is adapted to receive a removable lid 134. In an alternative embodiment, the sprinkler box 100 may include other methods of access, such as an access panel 142 on a side of the bottom portion 102 providing access to the contents of the sprinkler box 100 from inside the attic of the structure.

[055] After installation of the sprinkler box 100, the cover 104 and lid 134 may be covered with the structure's roofing material, such as roof tiles. A hole may be cut into the roofing material through which the popup sprinkler 110 extends when activated.

The hole may be left open or for aesthetic purposes, plugged with a removable cap that aesthetically matches the roofing material.

[056] Portions of the system may be supplied with individual controls. An exemplary set of controls are shown in Fig. 8. Such controls may be mounted, for example, in the bottom portion 102 of a sprinkler box 120, together with at least one popup sprinkler 110. In the alternative, the system may be mounted in any suitable location in a line leading to one or more sprinklers of any type. Sprinklers may be connected to a water supply 112 through a pressure regulator 114, a pressure gauge 116 and a shut-off valve 118. The pressure regulator 114 and pressure gauge 116 are used during installation to adjust the water pressure at the sprinkler box 100 so that the sprinkler 110 operates at an optimal water pressure, such as at about 30 psi or more.

[057] Having described sprinklers and other components of an exemplary fire suppression system, reference is again made to Fig. 2 which diagrams the system as a whole. It may be desirable to provide automatic operation of the system, so that the fire suppression system can be operated without human intervention. To this end, at least one heat sensor 80 may be disposed adjacent to an eave sprinkler and electrically connected to the automatic gate valve 42 of the plumbing system. The heat sensor 80 may be adapted to activate the flow of water through the gate valve 42 when the heat sensor 80 detects a temperature that is higher than a predetermined threshold value.

The threshold is preferably set above the highest temperature recorded in the geographic area, for example, at about 130° F, or higher. In the alternative, the eave sprinklers 34 and 36 may be connected to the main water pipe through an eave sprinkler plumbing system, independent of the roof sprinkler plumbing system, that includes a gate valve for activating the eave sprinkler independent of the roof sprinklers.

[058] The automatic gate valve 42 may be connected to an electronic control panel 82 for activating and deactivating the system. The electronic control panel 82 may be a dedicated control panel used only for the exterior fire suppression system or may be connected to other systems in the structure, such as an interior fire suppression system, a security system or a home computer network. Electronic control panel 82 may comprise a keypad connected to a home alarm system that allows the fire suppression system to be activated remotely through a security service, telephone, remote control, computer network or other instrumentality. The heat sensor 80 may activate the fire suppression system directly through the alarm system and the alarm system may also be adapted to sound an audible alarm when the system is activated.

[059] Suitable control systems for interior fire sprinkler control, for example, control panels and other system components provided by vendors such as Potter Electric Signal Company of St. Louis, Missouri, may readily be adapted for control of an external fire sprinkler system. It may be preferable to locate control components in the interior of the structure, such as in a garage or control room, for security and protection from the elements.

[060] A suitable control panel may comprise controls for controlling flow of water to one or more sprinkler zones of the system. For example, using the control panel, water may be manually supplied and shut off to desired zones. In addition, or in the alternative, the system may be placed in an automatic mode, wherein water is supplied to a sprinkler zone when an associated heat sensor indicates an elevated temperature. Likewise, an automatic mode may shut off the flow of water when the heat sensor indicates that temperatures have stabilized in a safe range. For example, water may be shut off after the heat sensor indicates that temperatures have been maintained below a lower threshold temperature for a designated period, such as ten minutes or longer. A control panel may, in addition or in the alternative, be configured for control from a remote location. For example, a control panel may be connected to the Internet, and controlled using a remote web browser. Suitable systems for remote control of devices using Internet-protocol network devices are known in the art, and may be adapted by one of ordinary skill for use with the invention.

[061] The control system may also include an exterior control panel for access by fire department personnel or other system operators. Exterior panels are sometimes used for indoor fire sprinkler systems, and may readily be adapted for control of a system according to the invention. The exterior control panel may provide all of the same control features as an interior panel ; or in the alternative, a subset of features, such as manual controls only. Optionally, an exterior panel may be protected from the elements and secured by a lockable weather-resistant enclosure. A key or combination for unlocking the exterior enclosure may be supplied to the responsible fire department, for use in the event of a fire. It is anticipated that a much smaller number of fire fighting personnel would be needed to protect neighborhoods in which the houses are supplied with external fire suppression systems. Using a master key or combination, a single fire fighter can readily protect a large number of homes by activating and de-activating their fire suppression systems in response to surrounding fire conditions.

[062] The plumbing system 40 may also include a flow switch 84, a bleeder valve 86 and a mixing valve (not illustrated). The flow switch 84 may be adapted to detect the flow of water through the fire suppression system and signal the alarm system 82 to sound the alarm when the fire suppression system is activated. The flow switch 84 may also be used to detect a leak in the system. The bleeder valve 86 is installed between the gate valve 42 and the sprinklers, and is used to drain residual water from the plumbing system when the system is inactive. In a preferred embodiment, the bleeder valve 86 includes a hose bib for connecting a hose through which the residual water will drain. The mixing valve may be installed to add a mixing agent to the water to increase the fire suppression qualities of the system. For example, the fire suppression system may be adapted to deliver fire resistant foam or gel products. The plumbing system may also include a connection 88 and a pressure regulator 90 for use by local fire personnel to supply water to the system, in the event that the utility water supply fails.

[063] In a preferred embodiment, an installed fire suppression system includes a plurality of roof sprinklers and eave sprinklers that operate to completely saturate the desired exterior zones of the structure when activated. For example, roof sprinklers may be disposed throughout the roof in a manner that provides complete saturation of the roof when the system is activated. Saturation of any given portion of the roof may be achieved directly from a roof sprinkler or indirectly through water runoff from the activated system. At least one roof sprinkier is preferab ! y instated to direct water to the <BR> <BR> highest point on the roof (see e. g. , Fig. 3) allowing gravity to spread the sprayed water across lower portions of the roof. The specific configuration of the sprinklers in the fire suppression system will depend on many factors, inciuding the pitch of the roof, the size of the structure, the type of materials used on the structure and the time in which complete saturation of the structure's exterior should be achieved to adequately protect the structure from an impending fire.

[064] Having thus described a preferred embodiment of the present invention, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. For example, most of the components of the exterior fire suppression system described herein are installed in a manner that provides protection from the external environment when the system is inactive, thus reducing corrosion and increasing reliability. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, it is contemplated that various combinations of the embodiments described herein may be merged into one or more systems. It is also contemplated that the fire suppression system can be implemented in any structure in any environment, including city, suburban and rural environments.

[065] The scope of the present invention is defined by the following claims.